App promotion can be very difficult, as you really have to find the right group of people who will be interested in using your app. Even if you have a lot of hype at the initial launch, without a set market segment, yours users will taper off quickly after the initial excitement wears off. This is something we saw very recently with Meerkat; they had a massive launch but quickly died out, raising important questions about how to sustain app promotion and app marketing.
One main channel of android app promotion is through the app store. However, ranking in the app store is generally a flawed process, as it is very difficult for many developers to get people to rate the app. Instead what ends up affecting your app ranking consists mainly of the name the app, keywords, and the app's description. Getting featured on the Apple App Store and getting Facebook ads are also great ways to aide with visibility and spreading awareness.As well, having a celebrity endorsement or having notable tech android reviews the app are both amazing for buy real app installs. But most importantly, you really want to do the homework behind your app promotion- do the research, do the user-testing, identify your target group. A simple but effective way is just to go on twitter and find a group of people who might want the app, and begin reaching out to them.
It is also important to note that you want to look beyond just the internet for app promotion. You don't want to forget the world you live in. More and more app commercials are going towards traditional media - advertising on tv, spotify, radio, etc. A great example of this is the Seamless App, which largely dominates the NY market. What they did that worked so successfully in NYC, is that they literally went to all the restaurants and supplied them with free plastic bags branded with "Seamless." So in a literal sense, targetting and approaching your target market can be incredibly powerful in establishing a customer base.