what is the difference between buying a game from amazon and buying a game from steam?

Oh boy.

Some/Most(?) Amazon games don't give steam keys.

amazon ones are usually cheaper.

Amazon comes in key form for games on steam And some amazon games don't have steam keys.

buying on amazon.com makes you have to get bored putting american adresses..

so Black Ops II will have a steam key if i buy it from amazon?

Protip: Go to said product on Amazon, hit Ctrl + F, type 'Steam', if no results then can't activate on Steam. If a result is found, read context and use brain.

9 times out of 10 the games are usually cheaper on Amazon. Coupled with coupons, rebates, and great bundle deals, there is very little reason to buy from Steam unless you're looking for an indie, older, or relatively unknown title.

A majority of what Amazon sells in the Core Download store are Steam keys, but always be sure to check each individual store page for that information. Just do a Ctrl + F and look for Steam.

^bump for awareness

More hassel.

Amazon doesn't accept paypal.

The URL in your browser.

Amazon sells only keys, not tradeables

Prices

Price depending on the game.
Payment options.

Price

For pre-order purchases if there are bonus items, they are only honored for purchases from the Steam Store.

Amazon only sells to USA residents, unless you trick it somehow. Also it's prices few times more expensive than those on Steam. At least in my region.

On a side note that regional restriction thingy is infuriating. I can buy my favourite singer albums just fine but their limited editions or singles I can't. Yet they freely sell me regionally coded DVD's and Blu-Ray's.