Purpose
This guide is intended for well meaning, yet socially inept guys attempting to find romance (or at least dates) through dating websites. Face it guys, the deck is stacked against you. There are many more single men looking online than single women. So, it behooves you to invest some time and effort to increase the chances the woman you email will respond favorably.

A word of advice – do not think that you can misbehave in interactions with someone because they’ve already told you they’re not interested. This follows the dubious logic that, since they’ve already rejected you, there’s no harm in (pestering them to reconsider, insulting their choices, or any other rude behavior.) Word spreads. Believe me, the online dating pool (at least among similar people) is much smaller and well-connected than you think it is. I keep running into people who know friends of mine. If you leave someone irritated with you, it is quite probable that you’ve just poisoned your chances with any of their friends or acquaintances. Don’t be “That Guy”.

This guide is very much more tl;dr than I was expecting. Writing a simple email to somebody you're interested in has many more rules than I'd originally thought. Perhaps I'm being overly prescriptive.

Introductory Email
The purpose of the primary email to a woman is essentially an initialization handshake. Basically, you are trying to demonstrate that:
(a) You are interested in them.
(b) You are interested in them, i.e. you have actually read their profile and are interested in the contents of it.
(c) You are not a creep, or desperate (okay, so some deceit may be involved here.)
(d) You are intelligent enough to be able to clearly communicate.
(e) If you are an advanced user, you can be unconventional, self-denigrating, or humorous. These are not amateur moves! If you do not know your audience, you will crash and burn. Try at your own risk. If you are an advanced user, you already know it. If you aren't sure, you are not.

The ideal introductory email is concise, opens the communication channel, and is grammatically correct. I cannot emphasize this enough: use proper capitalization, punctuation, and grammar. The email should be longer than two sentences; two sentences are not really enough to indicate to someone you thought about how to introduce yourself. However, it should also not exceed two paragraphs (roughly eight sentences). If the letter articulates every detail of why you think the two of you would make a good match, you fall squarely into the "trying too hard" category.

A good email also must include an easy launching point for conversation. This can be paired with indicating you read her profile. The easiest way to do this is with a question (i.e., "You indicate that you like Y. Have you tried Z?") Examples will follow below.

It is not necessary to do everything perfectly in an introductory email. It is imperative that you avoid committing any of the following mortal sins:

Mortal Sins
(a) Making the email sufficiently non-specific as to look like a spam you send to any halfway attractive female on OKCupid.
(b) Writing something so poorly (bad grammar and punctuation, no capitalization, etc.) that you appear to be illiterate. You aren't texting your friend from the bar. You're introducing yourself to a prospective date.
(c) Don’t ignore her guidelines. If she says she doesn't like cats, that is probably a preference. If she explicitly states she is not interested in any cat-owners, that is a rigid constraint. This means you should not bother messaging if you have any cats. Do not try to negotiate deal-breakers. She is not going to change her mind because you, the glorious stranger that you are, have contacted her to let her know how silly she is being. This is a really condescending attitude. In fact, this may be a worse sin than not reading her profile, since it indicates that you know what her preferences are, you just don't care.
(d) Lying. Misrepresentation, bending the facts, shading the truth, rounding up, using only old pictures. There are many ways to not tell the full truth. Most of minor and sometimes necessary to get along in society i.e. laughing at a less than hilarious joke. The things we hide because we know they are unflattering need to be handled delicately. Lies of commission (height, marital status, fitness level, etc.) are a really bad idea. If you need to outright lie to get somebody to be interested in you, they are going to be Very Annoyed when they find out the truth, as they inevitably will if you start dating. You will not only be dumped, they will dislike you.

Lies of omission are trickier. Obviously, some things about yourself are not really appropriate to talk about with strangers. Unhinged family members, painful personal history, and other topics are awkward early conversation, and aren’t necessarily their business anyway. A good rule of thumb on not omitting something important is, “Would she be really, really mad if she found out after I hadn’t told her?” If the answer is yes, you now have the problem of deciding when is the right time to discuss it. This is so dependent on situation that I can’t really cover it here.

There are a few venial sins which are not as severe as the mortal sins, but they raise the response threshold. For every one of these you make, your chances of a positive response decline. With a sufficiently good profile, you can commit some of these and still succeed. Another way to consider the situation is probabilistically. Your chances go down with the venial sins, but sometimes it is just a three-sigma day for you and it might just work anyway. A few scattered examples of success are not sufficient evidence that the venial sins aren't hurting your chances.

Here are the venial sins -- forgivable but not good ideas:

Venial Sins
(a) Misspelling a word or two, or leaving off some punctuation. Example: confusing "your" with "you're". It makes me wince, but if you're cute and your profile is interesting, she will probably reply anyway.
(b) Making her think too hard before replying. If you don't lob her an easy opener, you're pushing the actual effort in replying off on her. She is probably capable of it if sufficiently interested, but obviously she is more likely to swing at a slow pitch. Don't make it harder.
(c) Self-denigration. While it's good that you don't consider yourself God's gift to Creation, it's bad if you have to tell me ahead of time how bad you are at things. Trust me, if you're that bad, she'll notice without you pointing it out. This is akin to apologizing to somebody for being really rusty before sleeping with them. It's a rookie move. There's also no upside to doing so -- if she is inclined to be forgiving she'll forgive you anyway, and if she's disinclined to be forgiving, you're just highlighting your flaw.
(d) Overly effusive compliments. If you are emailing her, she can gather that you feel she has many fine qualities. Pick one or two that you can use as conversation starters, such as her taste in books or hobbies. A compliment is nice, but too much enthusiasm will make her question either your sincerity or selectivity.
(e) Asking to meet before successfully opening a dialogue, unless it’s clear from her profile that she enjoys this sort of spontaneity. Asking for a meeting in the initial email asks for much more commitment than an email response. If she is on the fence about you, she will be much less likely to make the investment of agreeing to a face to face meeting.

Tactically speaking, when opening negotiations with someone, it is better to get them to agree to a small concession early on. A desire to maintain consistency shifts their mindset to one of being more willing to negotiate. If you ask for something too big, many people will dig their heels in. However, if it’s just one sentence out of several that initiate a conversation, and it suggests something her profile indicates she enjoys, she can keep the notion in the back of her mind while exchanging emails with you. If she’s not sure she wants to meet you (and most people won’t be sure based on one email), she can still respond to the email without agreeing to a date.


Examples of Good and Bad Introductory Emails:
Example of a fairly bad email:
Your profile info says Norfolk, but you say San Diego. Where you at crazy? :) If your in Norfolk, have you gone to Virginia Beach Rock Gym yet?

Diagnosis: Venial sin (a) and (b), combined with half of mortal sin (c) (My profile at the time clearly said I was on business travel temporarily to Norfolk, so he obviously failed at reading comprehension.)


Example of a bad email, compounded with desperation:
(subject: OH MY!) You seem fantastic. smart. funny. and prett. and you name is great. my name is XX. message me back.

Follow-up after no reply: (subject: oh come on) give me a chance.

Diagnosis: Mortal sin (a)! Mortal sin (a)! Don't ever do this! He compounded this deadly mistake with a follow-up email badgering me to respond. Gentlemen, if you have to nag somebody to interact with you, you have already failed. More on this in Part 2: “I emailed her, now what?” Venial sin (d) is also blatant here, but the presence of a mortal sin makes it fairly irrelevant.


Bad:
hi just wanted to drop in and introduce myself , u have a very interesting profile , and look like u would b alot of fun , i love hiking and caving as well , i have hiked the appalacian trail twice , but dont get to as much as i;d like anymore , i have a 6 year old daughter and i devote most of my time to her. any waould love to chat with ya sometime , so hope to hear from ya

Diagnosis: Mortal sin(b). Mortal sin (c), since my profile clearly states I am not interested in children. His flagrant wallowing in poor spelling and punctuation is so severe, though, that it doesn't really matter whether he has one, fifty, or zero children.


Short and bad:
I just wanted to compliment you on your profile description it was very detailed and entertaining to read in a good way. You seem to be a very knowledgable and adventerous person which is really awesome.

Diagnosis: Venial sins (a), (b), and (d). Sufficiently non-detailed that I suspect mortal sin (a).


Decent but long:
When I read that you love reading both Larry Niven and David Brin I must admit I got weak in the knees. There really are simply too few women who appreciate good sci-fi, and those two are in my top five authors for sure. As you probably guessed, I'm also a sci-fi fan, and an engineer as well. And yes, of course, I also play World of Warcraft.

I recently moved to LA, and I haven't found the city very pleasant, but one of it's saving graces are the Ethiopian restaurants. The nearest one to Austin (my hometown) was in Dallas. Here they have 5 within one block of each other. I noticed on your profile that you were looking to try out Ethiopian food, so I thought it might be worth a shot to offer to take you to my favorite place. I'm certain we'd at least have a lot of interesting things to talk about.

This online personals thing is brand new to me so hopefully I haven't violated the rules of engagement. Asking for a face to face meeting on the first message might be a grievous trespass. Here's hoping you don't think so!

Diagnosis: Venial sin (c). Wins big points for noticing and complimenting me on my interests. Wins lots of points for noticing something I've indicated I want to do, and offering to assist me. This is the sort of email I would respond to positively, and meet face-to-face (in fact, this is from a guy I saw regularly in LA before I moved.)


Offbeat but okay:
I can't come up with any really creative and slick way to ask you out on a date, so I'll just go with clumsy: fancy a drink sometime?

Either way, judging from your science fiction preferences, go find some Greg Egan - our tastes are similar, and I'm certain you'll love his work. I got turned on to him when I was living in Finland.

-XX

p.s. and Logan's Run is one of my all-time favorites, though I bought the DVD over a year ago and haven't unwrapped it yet.

Diagnosis: A bit of venial sin (c), but it's limited and forgivable. Finland is a good hook for me to ask about in response. It suggests an author based on ones I listed as enjoying, which gives me another hook (to either ask for a title recommendation, or say, "Why yes I do like Greg Egan!" or...) A girl is more likely to respond conversationally to an email of this caliber, even if she’s not interested in dating you. It also isn’t particularly pushy – it asks if I want to go out for a drink, but then shifts focus to suggesting an author I might like based on my profile.

Part 2, coming soon (or whenever I get around to writing it), will be titled, "So I emailed her, now what?"