HG's current post count: 8,388,607 (as of this writing). A few possible ideas on how he arrived there:
He posted each of the 26 letters of the English alphabet. Roughly 322,638 times each.
He got extremely bored one night and typed out the works of Shakespeare... each word being a new post.
He didn't fail; he figured out 8,388,606 ways how not to write a post.
He was participating in the Vonage "Thanks a Million!" contest, and nobody told him to stop posting...
Whatever the case may be, we sure know he wasn't posting about service upgrades and new features! (heavy sarcasm)
Just kidding Bill! Now I got bored and actually sat down and typed this out. Thanks a Million for all you do! (no pun intended)