We'll do the initial web design for free, but you're going to be so popular that we'll need to take a small portion of revenue so that we don't go bankrupt from bandwidth fees! We can work this out later.
So, in other words, if Mr. Gaffigan isn't careful, he's going to end up paying a lot more than $35k for his site.
The $35k CK paid for his site didn't include continuing cost of continued hosting, bandwidth and administration. These guys seem to be offering to cover those costs indefinitely. So apples to apples, development cost is $0 compared to $35k.
So, in other words, if Mr. Gaffigan isn't careful, he's going to end up paying a lot more than $35k for his site.