Bitcointalk is one of the most popular discussion channel for Bitcoin, and Only account with specific status can post links to signature and therefore promote their website. Bitcointalk is great place to talk about Cryptocurrencies and promote your ICO. its a big help to all user of cryptocurrency when they know about bitcointalk and how it works. its a lot of learning you will know and understand everything if you read all about in bitcoin forum and maybe you can get an idea for that.