Marketing materials, sales letters for App agencies?

[zardon]

Hello there.

I'm currently freelancing here and there and am wanting to put together a landing page or some kind of website which I can point potential customers as an educational tool and a way to promote/market mobile apps, mobile websites.

I am wondering if anyone can point to a good set of marketing materials, sales letters, hard numbers (stats) or quotes, things like that that one could use on an App website.

I've got some quotes, stats from Google own mobile movement video and their own Mobile deployment platform GoMo, but I am interested in others too, especially sample sales letters or copywriting examples for mobile app developers.

Thanks.