There's a lot of signs there for bạn that some people just don't care about bạn that much, hoặc maybe bạn have all the wrong set of your online friends. On this site, there are some ways for bạn to tell if your Những người bạn are really your Những người bạn like they say.
#1 They never add bạn back, not even after a whole năm hoặc so, although they're on this site all the time. They just don't care about getting any new friend, that's all. Some people on this site never read their mail, others never add anyone back... It's not your fault, so don't take it so personal, okay?
#2 They're never around to comment...