Fitness you can always START with Social Media... Honestly, with a brand new site - this stage in the game, getting started, you would be the LEAST at risk of G Updates F**cking up your site if you were to launch it now lol... So what are you going with? MarketAds? CB? or combination? (MarketAds is, from all reviews I've read, im not personally in that niche, the best CPA network for health/fitness products such as supplements - as they specifically speciallize in that, whereas ClickBank would probably be your best bet for Info Products on the subject)... Just my 2 cents - oh yeah and IG, FB and Twitter would be good for free/cheap traffic... Depending on the GEOs allowed with each offer - you might want to look up tier 1 countries with hte highest rates of obesity lol .... I hear Germany has quite a few porkers per capita (something like 25% obesity rate) - and they definitely have $$ - US is way oversaturated on that IMHO