There is something greater than a social circle, the economic circle. It might not be for you but lot my contacts have transactional relationships with me, i.e., they have my details because they know I can offer something they have availed in the past and might someday need in the future, they trust me. And same goes for me, if someday I need my friend Tushaar's video and audio skills for some project I should be able to look him up instantly and message him rather than asking around helplessly within my social circle for his contact.