I think everybody who knows me knows that I love World of Goo and thousands of people also love World of Goo, but the birthday World of Goo In Rainbows style pay whatever you want deal made sure that everyone gets a chance at buying it, even those who don't particularly care for the indie darling of 2008.  And now that deal has come and gone, but now we get charts and tables with stats!  Delicious stats!  
 
The results are actually pretty positive despite the majority of buyers being cheapskates (except the Swiss.)  About 65% of the purchases were of the Windows version with the remainder split between Mac and Linux, weird.  The average donation increased over time possibly reacting to the amount of money 2D Boy makes or loses per download.  Any purchase under 30 cents was considered a loss, but it appears the average donation was about $2.50 give or take a few cents... they made money. 
 
And they did us a service and split it by country, too!  Brazil was the most "generous" while the Swiss averaged $5.37 per download, about what the game is worth about now.  Americans were cheap bastards as always, but bad economy... not our fault?  At least we beat Turkey and South Korea. 
 
They proclaimed it a success and yeah, I can totally see that.  They get tens of thousands of new potential fans and plenty of notoriety for this unorthodox, but unoriginal strategy.