Now this is an old one but its pretty relevant. I was chatting up a friendly girl in the cafe at my university. The interaction was awesome. We had a lot in common. Ended up talking about anime and adult swim for two hours. I lean back exhibiting confident body language and she is constantly leaning in, head resting in her hands, smiling giving me direct eye contact. In other words, she is interested. Unfortunately, I had a paper due tomorrow morning. I didn't ask for her number same night because I was following bad advice from a female friend: that I should wait until the second encounter before asking for numbers. (This was before I came to seddit.)

Anywho I met her a few days later. She was still positive but not nearly as much before. The conversation that day pretty much stuck on how busy we both were. I got her number and were friends on FB after that encounter. Both pieces of contact info are useless. All I get from her on FB are game notifications and she is a horrible texter. Taking anywhere from hours to days to respond if she does at all.

Either she's extremely nervous, lost interest, or just bad at communication. All of the above suck.

TL;DL Even if you're not going for a k-close or a SNL (like me), always get the number. Things grow state very fast. Its important to keep conversation going and arrange for a date quickly. Otherwise you and the whole affair falls flat.