Yes, they can. Unfortunately, you have to put a lot of effort into finding the right person, just like you would when doing other things. But, there is a plus side. Many times, people find that dating online through a service can be more easily and safely done than meeting a person somewhere else. A person can find out if the person is who they say they are. The actual experience is very different depending on what sex you are, though.
Ladies, I'm sure you've asked yourself "do online dating services really work?" and "how do I meet that special someone?" Let me tell it to you straight. You'll get innumerable messages from guys. To keep their attention, all you really have to do is reply and not act crazy. Or at least too crazy in the wrong way for that guy.
If a guy is hesitating about asking for your number or to meet, and it's something you feel comfortable doing, don't be afraid to do the asking to move things along. The worst that can happen is you fall back on one of the many other guys you're talking with.
So on to the profile. If you're not the type that needs to hear how pretty you are but are what most people consider average, then you can post a picture. Just don't make it very big or very easy to tell what you look like because you will get guys to send emails to you trying to get to know you instead of your picture.
As for what you write: show a little bit of your personality, but not all of it. Epic essays, samples of your poetry, and pictures of your family and pets and plants is just too much all at once. Let the guy work a little to find out who you are, they're more comfortable with that. Not only that, but all that info is fodder for stalkers and identity thieves.
And for all you guys, you have to ask yourself if these services for online dating actually works. It is much easier to jot off one, two, or twenty emails to start talking with somebody instead of meeting some random person on the street. They will still be hard at times even though they are online conversations. You still have to make that move.
Here's what you want your profile to look like to make things easier: write it like you expect her to read it after you've already contacted her. Don't sell yourself in your profile and try to get her to talk to you, share a few things about who you are. Things that make it seem there's more to you than the brief(!!). first message. And post a couple pictures. One that shows you having fun and doing something you love to do and another that shows you comfortable among your peers.
So do online dating services really work? They can if you do the right things in the right way. It's different though, conversations that would take minutes in the real world may take weeks online, but you can also get comfortable with someone in no time at all before ever meeting them.