One of the disadvantages online game retailers have traditionally burdened is a lack of trading. This is a good thing for companies like Amazon in a sense (customers get what they get and that's that), but people like trading their games, and overall this works out better for everyone. 

So with that we announce the spanking new "Amazon Video Games Trade-In" service, which by no coincidence has caused game retail giant GameStop's shares to take a swift drop.

As it goes, you send in your used games for credit on the website, not to mention an additional 10% bonus for items in their online video game store.

GameStop shares had risen 35% over the last three months, struck promptly by a 15% drop this morning following Amazon's announcement, falling $4.04 to $23.26, with the latter company's numbers off 31 cents at $64.50.

The news follows the unveiling of their Game Downloads shop and banding with the Open Internet Coalition. Seriously guys, stop being so cool.