How does a product sell out before it's officially released?WotC has sold the books. Retailers have paid for them. It doe not matter if they are not yet on store shelves because WotC has been paid.
Not necessarily. (Although I hope so.) Retailers have 90 days to pay publishers for books AND can usually return them in that amount of time, sticking the publisher with the loss. In fact, many brick and mortar stores (B&N, Borders, etc.) will wait 90 days to pay the publisher, return the books before the 90 period is up, and then RE-order the same books and not pay for those for up to 90 days. Authors have been complaining about this for awhile now. If the publisher doesn't get paid for 6 months, neither does the author! It's all fun-and-games when you're trying to keep up with Amazon these days.