While I think the idea of this article is true, I think it's a bit unfair to compare the number of mobile apps to the number of web sites. Yes, there may be 350 million websites, but how many of those actually offer a valuable service? I think that the number of worthwhile websites is easily less than 400k. Same with the phone app market: there may be 400k apps, but most are crap. Honestly, I think that the web and mobile probably hover pretty close to each other in terms of the number of useful applications.