Truthfully I'm not a fan of adding people I don't know to any type of social networking. Is there a guideline for adding/accepting friends on this site? It makes me a bit uncomfortable if that makes any sense (all of my current requests are from males.)
I don't add people on here, except when I promise to speak to them in an answer (which has been a few times). In general, I get requests. I always accept, but if at any point during a chat they get nasty or disrespectful, I block them. For the most part, though, the people I speak to on here are very nice individuals and we get along well.
Most do it if they like the answers/questions from other users. And in some instances, some seem to click. Whenever I'm sent a request, I always check their activity/answers/questions before I accept. If they have zero activity, and seem a little strange, I decline. Most of the time, I accept in any case.