Facebook is letting you take "liking" something to a whole new level with the introduction of a "Buy" button within users' posts and news feeds later this week. The newest challenge to your impulse control begins on Thursday.

The move is being viewed as a direct challenge to Amazon.  From the Business Line:

In an image of what this feature looks like, a ‘Buy’ button sits in the bottom right corner of the ads that users normally see as they scroll through their Facebook news feeds. This feature is currently in its test phase, so it is being used only for a few small and mid-size businesses in the US.

The “Buy” option will be available for specific products on Facebook’s site and mobile app starting Thursday.

Elsewhere in the social media e-commerce wars, Mark Bergen juxtaposed the Facebook news with word that Twitter has reportedly acquired a payments start-up.

The company said it planned to acquire CardSpring, a San Francisco-based startup that allows developers to write applications for credit cards, discount coupons and other payment systems. Its platform is aimed at linking e-commerce with brick-and-mortar sales. Online shoppers can collect sales offers, synch them with their credit card and then collect them at stores. For Twitter, the company offers an existing payments infrastructure that is not built solely around impulse purchases. 

There's no word yet on how this will impact the special art of user reviews.