Amazon Associates is the partner program the company uses as part of its affiliate advertising programs, allowing customers to make money advertising Amazon products.
Associates can now simply click a link in the toolbar to send a link (replete with sales-y text) to Twitter as part of their shopping and selling experience. Amazon gets a sale, Twitter gets traffic, and the associate gets revenue share. What could possibly go wrong?
Linking to Amazon or other online retailers is obviously nothing new, though Amazon has been particularly successful in using its link networks for both sales and to garner higher Google rankings for organic advertising.
This new program does introduce an issue related to link fraud, where spammers and scammers leverage URL-shortening services for spam links. Currently there is no way to verify that the link you click actually goes to Amazon. It's a bit surprising that it decided to use an URL-shortener that it doesn't own, though I suppose the network effect of the URLs helps perpetuate the life of the links.
There is also a risk of nondisclosure wherein in Twitter users attempt to push products that offer some kind of gain to them that they don't clearly state to you. While I understand the argument for disclosure on blogs and media in general, Twitter remains a playground for people to post whatever they want. I highly doubt all the celebrities with accounts would bother wasting their precious time if they weren't posting for their own gain.
Interestingly, there is no mention of whether Twitter is an Amazon Associate, suggesting that Twitter won't see any of the revenue share. I'd like to think that they cut a deal that gives them a piece of the pie, but to date we haven't seen Twitter monetize itself too effectively.
Twitter is quickly becoming the flash news vehicle for everything from news alerts to product placement. And based on a very quick review of my Bitly account, Twitter users just love to click on links. But, I still have to wonder if Twitter will ever get beyond its current role as a marketing tool?