The Weinstein Company has had to cut all sorts of "creative" deals here and there to get as much money as they think they can to stay afloat. One of these deals is an exclusive-rental arrangement with Blockbuster, so only Blockbuster can get rental copies directly from The Weinstein Company. (Of course, mom-and-pop shops can go to Wal-Mart and buy a few copies to rent, though most of Blockbuster's major competitors will never carry Weinstein titles.)
Still...when you take a look at the movies that The Weinstein Company has released, you wonder how lucrative this deal is for either company. What's the market for these titles? Regardless of what you think of their artistic merits, from a financial standpoint, they're not very profitable.