Carmel informs us that he's seen torrent sites with "500 seeders and 300 leechers" and has received emails from people who initially stole the game but ended up buying the full product; unsurprisingly, they make up a "very small percentage." He concludes, "We're doing ok, though. We're getting good sales through WiiWare, Steam, and our website. Not going bankrupt just yet!"
Although Carmel takes it in stride, this is probably a good time for us to reiterate that the charming and fun World of Goo was developed by 2D Boy, which consists of Carmel and his design partner, Kyle Gabler. We want more goo, so please support the 2D boys properly.