Bitcointalk is a discussion forum where topics like Bitcoin, Mining, Altcoins, Development etc. are discussed.  From there you can learn a lot about crypto.  But along with this forum also provides some earning facility.  Here you can earn by some means like you can go to service thread and you can offer some of your services like (marketing, developing, graphic design etc.) on the other hand through signature camping you can earn some amount weekly but it requires high profile.  Rank.  Which cannot be achieved without getting  merit.  And there is another medium which is Bounty which you can do but here the income is not fixed amount or guaranteed.