[I wanted to get your thoughts on how important building Pre-Sell pages instead of direct linking are? Could this be the reason 99% of PPC marketers fail?]
First let me say that I do not believe that 99% of PPC marketers fail, just 99% of PPC marketers that use pre-sell pages fail. Google considers pre-sell pages to be bridge pages, which are a violation of AdWords policy. Don’t use pre-sell pages and you substantially increase your chances of success.
I believe the overwhelming majority of PPC marketers succeed if they take the time to learn the accepted policies and best practices of PPC marketing.
I hope you can understand my error, after all, you didn’t mention that you weren’t using AdWords, which is the primary provider for this type of advertising, even within the mobile niche.
Having said that, the reason Google prohibits the “Bridge Page” is that users generally do not like the practice. Where possible, I would use an offer page with your own sales copy that submits to the order form/shopping cart/signup form. Skip the intermediate page if the affiliate manager permits it, an otherwise direct link to the AM’s sales page.