Somewhere between Black Friday and Cyber Monday, this Holiday season I’ve experienced a Twitter Sunday – with the best accessory deal I’ve ever scored. It was the Brooklyn based uber trendy Hayden-Harnett design duo (@hayden_harnett) who I happen to follow on Twitter, announcing their Twitter-exclusive 80% off sale on a long-time-craved Corcovado Turnlock Tote in Patent Black. Despite the early Sunday morning, all handbags and other items offered exclusively to their followers were gone within minutes. It was a moment when I realized my Twitter connections don’t only provide the emotional value, but also commercial.

This Holiday season my Twitter friends shared exclusive sales, special discount codes and rare finds, saving each other time and money. It was the first season Tweet Commerce really took off, and if I could make one prediction for 2009 it will only continue to develop, as more brands realize the value of constant connection to their consumers.

In addition, clever entrepreneurs are already realizing the value of these tweets and building applications around them, organizing the data like CheapTweet.com whose slogan says “scouring Twitter for deals so you don’t have to”. Online invite-only sites such as Ideeli.com (@ideeli) are using twitter to alert their users about new sales, and e-commerce brand eLuxury (@eluxury) sometimes share “secrets” like this one with their followers: “A little secret for the grapevine; starting tomorrow take an additional 30% off sale items. Shhhhhh”.

Call it Tweet Commerce or Social Shopping 3.0, but if you care enough about your favorite brands to follow their daily ramblings, you might score some great deals along the line. Now when people ask where I got my new gorgeous tote from, I say without thinking twice – on Twitter!

@yuliz