Would you include your app in a bundle offer if you could get it downloaded more?
'Bundling' is a common marketing technique to offer users more value for the money they're spending. It's been used to distribute desktop applications for years and some mobile developers are thinking it's time this sort of thing comes to the app stores.
There would be obstacles to overcome the markets, but I believe this could be a good way to help developers promote apps.
Appadvice.com offers an interesting article detailing their vision for how this process could work.