1. "Create compelling ads at an affordable price..." is way too pale, almost invisible on my laptop screen
2. Clicking on "Business Users" shows "Free!...". This should have a "how it works" or "why it's free" link right there, because that's the definitive question I have after reading the testimonial (which is also set in a way too pale color by the way)
3. I haven't even noticed the Free banner wrapped around the cow, because frankly the cow illustration looks out of place and I just skipped over it altogether. The illy is more fit for a Kinder Surprise ad rather than for your type of service.
4. The service being "free" does not correlate well with "set your budget" step on the right hand side. Also the width of "Start now" button is not the same as the width of the panes on that list.
5. IMO the name is awful. The "yo" part specifically. In fact the "yo" coupled with a winking cow implies "yogurt".
6. The way I understand it, your major proposition is an ability to easily post to multiple ad networks. THAT should be highlighted on the page, and the list of the networks should be readily available for inspection.
7. The availability of the templates is not important. Perhaps I am wrong here and capitalizing on the lack of rudimentary Photoshop skills is the next big thing, but consider the following. The fact that "Start now" leads to the page full of templates (none of which I like) made me not want to proceed to the next step even for the evaluation purposes. This in turn means that I didn't get to see the list of your ad networks and geo targeting goodness.
8. In the light of #7 it'd be great to have a Tour section for those who are curious but not quite ready to "Start now".