Try to promoting your app using App Banners. It's very simple and effective.
Put one line of code to your company or product website and on iPhone you get this:
On iPad you got also app screenshots!
Simply add the following meta tag to the head area of your site html.
<meta name="apple-itunes-app" content="app-id=0123456789, affiliate-data=myAffiliateData, app-argument=myURL">
Replacing the value for app-id with the iTunes identifier for your application.