The Last Podcast questions these numbers but I think the logic is bad. The claim wasn’t about visitors, it was about network increase – i.e., the network is being used more and more.
And if the network is being used more and more, that means we’re gaining ground. Good news indeed.
FWIW, this stats systems are all funky but Compete.com shows Podshow.com as having 3.7+ million people drop by in December. Alexa shows growth in 2007 as well.