This is a worthwhile move for him because the marketing he would recieve from spending that many credits couldn't be nearly as worth what attention he will generate from this contest.
Just a few weeks ago, I bought a spot on Problogger's Entrecard widget. Over the course of the day I got about 60 clicks. I paid around 250 EC credits for that 24 hour placement.
Now, with the new Entrecard system in which the price floats up with the demand, I would likely have to pay at least 1000 credits. Simply put, it would not be worth it. Although you might not be able to afford a spot on John Chow's or Problogger's widget, there is no denying that a sound marketing plan could field good results from those 10,000 credits.
Click here to check out John's Contest page. If you're entering like me, good luck! And good luck to me!
Are you entering the competition? Don't forget to comment!