My thought centers around brands having the opportunity to communicate in this realtime channel with products/services that may be of interest to followers. For example, highlighting a unique product featured in a live fashion event or a limited-availability shoe featured on TV show. 

Twitter could offer the brands an expanded tweet (see: http://bit.ly/zrknPq or the tweet itself in my Favorite tweets) to expose the product with just the right amount of “more information” that may or may not encourage the referral traffic back to the core branded commerce site for purchase. 

Think of it as window showing/shopping for the brand & consumer. Don’t like it? :: keep on reviewing tweets. Like it? :: Click to add to cart on the brand’s commerce site. 

This may or may not be in the cards, but it’s evident through the testing with Amazon and iTunes (see: http://bit.ly/xkBJiA) that Twitter is testing these waters. 

And I find it very compelling for brands to introduce commerce event through a tweet. And if offered as a promoted tweet, a potentially valuable ad unit for Twitter.

Only time will tell.

Jacob’s comment about audience engagement in Twitter is spot-on. I’d like to see brands and companies like P&G do more with Twitter’s expanded tweets. Just Tweet a link to an Amazon product page, or an app from the iTunes App Store, and see the beautiful interface that Twitter is giving to this content. Engagement + Referral traffic for commerce could be a huge offer for Twitter and is likely already on their roadmap.

But that means Twitter needs to continue to expand their reach into solid mobile experiences with better curated streams and filtered views (even some that are geo-located). 

Twitter has big opportunities in front of them, and it doesn’t carry the weight of the Facebook platform on its shoulders. Adam’s team appears to be cautious & calculated, but on the right track.