Viral user growth simply involves current users recruiting new users. The real magic happens when each user brings in more than one new user, creating an exponential growth rate.
A Marketing Sales Channel (MSC) is a way for your business to reach potential customers. It can be through the internet, television, radio, print ads, or even person-to-person contact. There are many different types of MSCs, and each has its advantages and disadvantages.
The Agile methodology is an increasingly popular and effective way for different types of development companies to create, test, and present their products -- especially software -- to the public market.