Shutterfly is a popular service for printing photos, making stationery and building photo books. Despite a a stock drop of 12 percent when Amazon announced Prints yesterday, we'll have to wait and see if there are any long-term issues for the company. That drop was Shutterfly's largest single-day decline in over eight years, but analysts told Bloomberg it was an "overreaction."

Customers in the US are expected to spend $2 billion for online photo printing services this year according to market research firm IBISWorld, so it's easy to see why Amazon would want a piece of that. Couple that potential revenue stream with the company's existing photo storage services and Amazon should be able to grab a nice chunk of that tally.