Doesn't this seem HARDER than just buying it online with paypal/CC to start with while making free advertisement by your tweet?
I mean the steps below sound more of a pain that just doing a paypal/CC purchase, with more wait time staring at your twitter waiting for that reply tweet you must RETWEET:
Cardmembers tweet special product #hashtags for the product they want to purchase with their synced Card.
* Cardmembers then check their Twitter mentions in the @ Connect tab (https/twitter.com/i/connect) for a response from @AmexSync containing a confirmation #hashtag. Tweet the confirmation #hashtag within 15 minutes of the response from @AmexSync to confirm the purchase.