If you're managing a mobile app that has social connectivity to G+, or Facebook then you can encourage additional app downloads by encouraging "deep linking".
This article from: thenextweb.com explains the technical detail -- but for merchants who are tasked with making technology strategy decisions let me explain what it means in real world dollars and cents:
Deep linking in content means when a person using a native app shares content on android or ios via Google+ (this works on Facebook as well, but it's a different set of calls that need to implemented) and a social recipient (such as a friend, family, or co-worker) follows the link, then that social recipient is prompted to download your app to view the content. For example sharing a deep link to a product - when followed would open your application and navigate to the product. Our AnyCommerce SDK already supports the ability to do this real easily (for example if somebody follows a link from Google shopping it doesn't just load the app, it loads the app in the browser AND immediately navigates the person to the product).
So if an app can encourage it's users to share content with deep links it can give apps an almost viral property to them. Of course the app product manager need to decide if it would be better to in HTML so that a potential recipient isn't dissuaded from viewing the content by needing to download an app. I would assume an HTML preview with a deep link for more information is probably the most palatable balance for most merchants.
Ultimately there is no right answer for everybody. Long term app downloads mean when the great switch over to app based search occurs then the person with the largest installed base (of qualified buyers) becomes the #1 store in their industry.