Directly from their What Is Woot Page:

What is Woot and who's behind it? Woot.com is an online store and community that focuses on selling cool stuff cheap. It started as an employee-store slash market-testing type of place for an electronics distributor, but it's taken on a life of its own. We anticipate profitability by 2043 – by then we should be retired; someone smarter might take over and jack up the prices. Until then, we're still the lovable scamps we've always been. But don't take our word for it: see what the online community has to say at this Wikipedia article.

I see only one item, do you sell anything else? No. We sell one item per day until it is sold out or until 11:59pm central time when it is replaced (see next entry for details). However, each item we sell is in stock and typically ships within 2-3 business days.

What is the schedule for new items? The short answer: we offer a new item every single day. The details: a new product is released every morning at 12am central time, seven days a week. (If you're not a morning person, this can be described as every night at midnight. Better?) If a product sells out during its run, a new item will not appear until the next release time. You will know if a product is sold out, because the main page says "SOLD OUT" instead of "I want one". (Clever, eh?)

I missed yesterday's item, can I still get one? No. Each woot.com product is discontinued at 11:59pm central time. That's that. Period. We may get more at a later date if we're lucky, but we offer no guarantees, we allow no backorders, and we have no waiting/notification lists. Too bad.

… they just sold to Amazon for $110 million