I really think that after a certain point you are wealthy enough to stop taking every chance of making a buck. That said if I owned coinmarketcap for a week I'd probably flood the site with such scammy ads and I think nobody can blame me for it, but I suppose their owner is a multi millionaire so I don't think he is desperate for ad revenue. Big companies like Facebook or Google that have become sort of like institutions should look at the ethical side of such questions and I think coinmarketcap is big enough to start thinking about it's public image and the way it influences the community.