I used Plenty of Fish a few times. It's easy to use which is probably its biggest plus.

I've had both good and bad experiences with internet dating. The good is that it's pretty easy to start talking to someone. Their interests are right there in the open as is what they are looking for so you won't waste your time striking up a conversation with someone who's 1. Not your type. 2. Looking for something totally different. And being that your initial contact is through an email, there isn't any pressure of trying to carrying on an interesting conversation right then and there.

The negative side though is you don't know who you are talking to. Most people use internet handles and not their names and it's usually not a requirement to include a picture (or the person can use a false picture). That's why it's important to talk to a person a few times before setting up a face to face meeting and meeting in a very public place (and letting someone know where you'll be). Use your intuition-if something doesn't feel right...it probably isn't. And when you find out the person's full name...google it (or run a back ground check). I started dating someone, after a few comments he made I got the impression that something wasn't right...did a quick google search and found out that my hunch was correct.