Amazon's health platform could send a lot of business to Talkspace.Talkspace (TALK 2.21%), the provider of virtual behavioral-health services, just made a move that builds on the bull thesis for the stock. Thanks to a new collaboration with Amazon, there's a good chance that it will be able to grow its revenue significantly faster than before.But Talkspace isn't exactly a low-risk pick, nor is its success inevitable. Let's break down the importance of its Amazon deal and analyze what the business is still s ...