Spammers are usually short of money and therefore they can't invest in Yobit ICO. If there are no decent people on their forum, there is no way they can gain investors from their own forum.
When you have over 300K posts on your forum in a month, Google surely gonna crawl many of those and list these on Google Search. When you have organic crypto-oriented traffic coming to your site, even putting a broad header with 0.5% click-through rate can give you handsome number of investors.
"If you got big money, think of the bigger picture" - Yobit