Heyzap allows any website or blog to take the most exciting Flash games and put them into their website. This results in the website/blog having increased traffic, user time of site and engagement. When youtube got video out everywhere over the internet, it changed the entire experience of the internet.
The goal of HeyZap is to be the "YouTube of casual gaming" by giving site publishers a way to embed more than 6000 casual Flash games into their sites with a single embed code. Their business model (more detail from TechCrunch) is to collect revenue from ads within the games using the MochiAds ad platform and share some of that with developers. The publishers using the code don't get revenue, but get increased traffic to their sites.