The decision to bring Steam over to the Mac has already started to pay off for Valve. New Apple gamers accounted for 11% of all purchases on Steam in the first week, meaning Valve are more than happy with how things are going. Kotaku point out that this could just be an initial rush for content but also state that the brilliance of Steam is the constantly updating catalogue of games and shockingly cheap deals/bundles. The free-to-play Portal deal (still on until 24th May) was another little boost for Valve with 1.5 million new downloads since last week. Despite it running slower on the Mac, Portal is apparently five times less likely to crash than the PC version. A stat to be proud of though likely to cause a few fanboy arguments too.