I was wondering whether the ICO tracker websites like
https://icotracker.net/ get coins/bounties in exchange for promoting ICOs?
They are probably profiting from the referral payment that some ICOs have. They advertise the ICO and receive something like 10% per investment that came from their website.
Or just flat fee advertising costs?
Taking a look at the site, I do not see any indication of them getting paid to promote a project. But they may not be disclosing if they are.
How can we know that the tracker sites are promoting things fairly?
You can't. Do your research and don't fall for scams.
(p.s: 80% of ICOs are scam)