There is a bigger world out there other than adwords. Adwords is a good way to get your feet wet, but after that its affiliate marketing.
Google is very very BIG company...yahoo and bing are nothing to do with Google....I thinkg google getting strict now because they focusing on quality search engine content right now...
Well for me adwords have been really helpfull all the time but yea thats true they very strict upon the TOS, But due to spam protecting and by being leader of the internet those Policies are required to them.
Facebook ads are good but they haven't yet set it up like google where people can put ads on their site and make $$$. adsense is on many people's sites and because of that reaches many more people then they would have if they just had ads when we search on Google. Facebook is doing well but it's not at the point that it will over take google.