I feel very "bearish" towards dating sites. People convince themselves they are saving time meeting more possible "matches" in less time but they forget that meeting online is not the same as in person, "turn-based" chat is different than "real-time" chat.

Some years ago randomly I met a girl online, that most of men (based on her picture) would wife up. I was living abroad at the time and we were only able to meet in person some months later. After few minutes in the date I could see that we would not go anywhere. There was a lack of "real-time" empathy and I hated some details in her personality that I couldn't realise before meeting her (not her look, surprisingly she was even more beautiful in person than at photos). If I had met her in person instead of online, I would have saved months of my life.. I will not do it ever again.

edit: Because of her I met my gf of 5 years, but that was just serendipity working, not because of a dating site.