There's a lot of signs there for Ты that some people just don't care about Ты that much, или maybe Ты have all the wrong set of your online friends. On this site, there are some ways for Ты to tell if your Друзья are really your Друзья like they say.
#1 They never add Ты back, not even after a whole год или 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...