does zapak miniclip gamegecko etc get money from advertisements or what?

Yup, the reason is hits, the more the hits ur website gets the more sponsors are likely to sponsor it.

The websites make money from selling banners on the web pages, they even associate with brands and make a game specially from them. This is where they make chunks of money! And this is their main source.

So there is loads of money that comes in - also the games on the websites are free but if u want to download it, it costs u money.

So there is enough money to keep the website alive :) hope u got it!

most likely advertising thats how any profitable "free" organization makes money

Yeah the ads on the site give them money if they have enough visitors. And some sites sell games and or lease games so that people can put their logos in it. Miniclip used to do this.

You are right, money for advertisement, the more famous your site is the better money you get. Right now miniclips rank in the top 500s for most popular site. So think about how many people want to post on there their ad. You shoulda see this game: http://www.fallensword.com/?ref=314270 it pay player game point for clicking on ads.