I really, really dislike this idea. This sub has some misconception about how making friends should be and it encourages being fake and ignoring your own needs in order to make friends. This is wrong.

Listen, if you don't like someone, you don't hang out with him just because he might show you his friends. First of all, if this is your approach to life, it's needy as hell and you should work on it. You shouldn't suffer just because you want more friends. If you feel like you don't have enough, so much that you need to manipulate others and act in a specific way (that sometimes isn't like you at all) just so they'll think positively of you, then your problem isn't social skills. It's your lack of confidence in yourself.

Second , hanging out with someone just because he can show you more friends is selfish as hell and shouldn't be done under any circumstances. It's like you'd date someone just because she'll give you experience at dating. It's ok to like a girl and date her because of both reasons (you like her and the experience), and it's ok to hang out with someone because you enjoy his company and he might show you other friends, but don't waste someone's time by using him. That's disgusting.