As mobile devices has become the new primary source for entertainment, news, utilities etc. Users love to interact with their favorite products and services through their pocket mobiles inspite of using their laptop or desktop. Every big or small brands are interacting with their customers and prospects as they are catching on to the increasing importance of mobile. 
Many developers or marketers are realizing that it is not enough to simply launch an app and forget it; they must have a clear Pre launch & Post launch strategy to drive awareness to capture the interest of their customer base and prospects. In fact, they are developing an app by considering their priorities. 

Most common mobile marketing channels:

1. Ad Networks: Ad networks place your ads on other publisher's mobile and web apps
2. App Discovery Platforms: Ad Networks which specialize in mobile app discovery
3. Cross Sell Promotion: Placing ads for your app on another, complementary app, usually within the same publisher and segment
4. Incentivized Ad Networks: Ad networks offering users an incentive (free offering, game credits) to download your app
5. Search: Users discovering your app via mobile search
6. Social Media Marketing: Mobile apps on social networks (e.g. Facebook, Twitter).

Hence, there are many factors and channels that an app marketing strategy must include based on conversion rates, user quality and install volume across various channels, geographies, app categories, and user segments.

Social Media App Marketing – engagement based on social elements like users inviting friends to use, rate, review a mobile app via a social network is pretty good  because high volume of users are joining social media networks like Facebook, twitter, Pinterest, tumblr, flickr, stumbleupon, google+ etc to connect with their friends. If we consider three major measures: conversion rates, user quality and install volume then games, travel, social apps, and geo-targeted apps all benefited using social marketing channels which played pivotal role in driving high quality of users at large volumes.

The challenges involved in successfully marketing an app differ greatly from what brand marketers are used to with digital and traditional channels. What can help you out greatly depends on what kind of app you're developing, who is your target audience, and most important how much is your budget. As these are the factors which will prioritize your key marketing strategies for your app marketing plan.