OK, two questions. First off, how many people actually subscribe to online personals? Meaning, which of you all post to sites that might allow you to find an a date with another person (I’m not sure exactly how those sites work and perhaps someone could explain). Secondly, why do it that way? Does it have to do with time constraints, your location, or are you just completely fed up with whatever dating “scene” (i.e. club, bar, etc.)?
A friend of mine met her husband through an online personal, so I’ll answer with her experience in mind.
First of all, the reasons why she, at least, chose to use an online dating service was because she didn’t like to go to bars and clubs (she rarely drinks, and she doesn’t like superficial people). For those reasons at least, I agreed with this method. And not only didn’t she go to bars and clubs, but as you mentioned, her schedule didn’t allow her to meet many men IRL. The few she did meet turned out to be very wrong for her for various reasons. OK, that could happen online too, i.e., you date people you meet online and they turn out not to be “Mr. Right” or “Ms. Right” (if you’re a guy). This happened to my friend before she met The One For Her.
In any case, the online dating services work like this: You can LOOK AT the ads already there for free. If you’re interested enough, you pay a monthly subscription. Then you can post your own ad, and REPLY TO ads posted by others who interest you.
A couple of years ago while my friend was dating men she met through her online dating service, I perused some ads just for the hell of it. I was unattached, so I figured what the hell, why not look, since I’m not a bar/club person either. The overwhelming majority of the ads I saw were posted by men who shared few or none of my interests (and/or were interested in things that repelled me: most of them were major sports fans for instance), and on top of that even the men my age (40 at the time) were specifying interest in women under 30 or 35 with very exacting types of physical characteristics. Me, I didn’t care what color a guy’s hair or eyes were, and I wanted someone if not my own age, within +/- 5 years – an equal as it were. But these guys in the ads were all too specific on physical preferences and not enough on a woman’s character or intellect. So I got disgusted and didn’t pursue it beyond this.
Then again, I should mention that there was also a major attitude difference between me and that friend of mine. She wanted to find the “right guy,” get married and have kids. My attitude was “I’d LIKE to find a suitable romantic companion, but if I don’t, so be it.” So she was a lot more persistent about weeding through the chaff than I was.
It paid off for her obviously; she found her Mr. Right and they were married this spring. And, I suppose, staying off the personals worked for me as well, since now I DO have a man I’m totally crazy about – who I didn’t have to meet in a bar, who is intellectually gifted and well read, who speaks his mind, is honest and loyal, doesn’t follow sports of any kind and is 38 to my 42 besides. 
Currently doing the online thing (and asking for help with tweaking my ad here.
Why? I don’t meet anyone at work, and I don’t drink, and none of my friends have single friends they’re clamoring to fix me up with.
How? Posting is free at most sites – if you want to respond, there might be a monthly fee, as Yersinia mentioned, or you can buy X number of credits, that you can use when and as you see fit – to IM someone, send an “I’m interested” “smile” or “wink” with no personalization, or write an email. I think the latter method is preferable, but some sites do one and some do the other. (Note that most monthly-fee sites renew automatically, and make you go through a multi-step process to cancel.)
Is it worth doing? Sure, why not?
I have been dating a man I met online for almost two years. Before him, I dated men from those ads for a few years on and off. All but one of those men I’m still friends with. I never met anyone that wasn’t exactly what they said they were in their ad.
The funny thing is that my current bf was more playing around when he posted his ad while goofing off with a friend of his (therefore, the pix was silly and so was the ad). I had subscribed to match.com and I was showing a girlfriend of mine one night (kinda late after a few drinks) and we saw his ad and laughed for 15 minutes. We emailed him for the fun of it and it ended up being the best thing I ever did. He is an incredible guy who just got shy around women that he had a romantic interest in.
I highly recommend it but 1) be careful 2) don’t expect everything to happen right away. It’s exactly like dating any other way except that it increases the chances of a first date. From there, you have to really find the right chemistry. Do it in fun, not in desperation.
Well, I do drink, and I do go to bars. But who the hell meets somebody at a bar? The people you want to talk to at bars are the people you brought with you, and any cool people at the bar aren’t there by themselves, they’re there having a good time without you, of course.
Then again, the personals market is probably better for people my age (23) because we do seem to be a generation who dosen’t go to church and has given up on meeting people in bars, and where else are you going to find them?
I’ve gone out with quite a few people I’ve met on the online personals, had a sort-of relationship with one and might be working on another now. But it’s something my friends and I do for fun and for the people-watching aspect of it. You can’t take it too seriously.