So I’ve been single for about three years and have signed up for a few dating websites in that time. I tried the paid sites, but they were crap and I never got anywhere because no one else was paying for them, so I went to the free ones like Plenty of Fish and OKCupid. I met a girl on one of those sites (I’m a guy) and we went on a date last week. She was great conversation and quite intelligent, but there was no attraction. I could see myself being friends with her, but there has to be some level of attraction for me to date someone. And I’m not talking just physical attraction, I’m not that shallow. We have a lot in common, but I just didn’t feel anything for her. The other problem is that she’s pushing for a physical relationship, if I hadn’t had to leave the date early she would have wanted to take it there that night. I’m not that easy. Now she’s wondering if she did something wrong and I have no clue what to tell her. Any thoughts?
LemonVibe 
[The hardest and best thing to do is to just be honest with her. She thinks there’s a specific thing she did, when really you just aren’t into it. It’s hard for any moderately attractive girl to understand why there is no interest from a male. Maybe it’s sexist but whatever. I’m usually baffled when I get dissed with no explanation. So I understand why she was pushing for more toward the end; a last ditch effort to get you to show interest. (Which, btw, we all do, subconsciously from time to time because it’s a human instinct to want to be liked.)
Anyway, I assume your conversations post-date have been either via the dating site or texting? If so, just come out and say “I had a good time the other night but I’m sure you felt it too; we’re a little more friendly than relationshipy. I’m glad I got to meet you.”
It sucks to have to say, and it hurts to hear, but you’ll both be better off for it. She won’t sit around wondering what she did wrong (nothing, you just weren’t interested in a relationship), and you’ll be able to move on without lying to her to spare her feelings.
Hopefully all you want is a clean break. It will be more complicated if you actually want to peruse a friendship with her, which I hope for her sake that you don’t.
[If you are sure that no possible relationship may occur between the two of you, do her a favour by being honest to her. However, please be mindful with your words as they may affect her negatively.
First, you may need to tell her the good qualities you noted on her. You may state how you find her intelligent and how both of you have a lot of things in common. Also tell her how much you’ve enjoyed her company.
Then proceed with the stingy part. Tell her that you have not felt any connections with her and, for both of your interests, it may be well-off if you both find another dating partners. This may hurt her, but it would be best to tell it to her directly before she her feelings develop more. End it with another positive note. You may tell her how good she looks with her dress or how the earring fit her well.
You may need to minimize any communications with her. The more you communicate, the more she’ll assume of possibilities. This may hurt her but the sooner she’ll get hurt, the sooner she’ll fix herself up.
[Pretty much agree with both Erica and yomar. Some people like to be blunt when they’re letting someone down (as Erica advocates), and others like to couch it in a little more sympathy (as yomar advocates). I think whatever style works for you is fine. Just make sure you are clear that you’re not interested in anything romantic.