The Daily Cartoonist has a list of the comics published on GoComics.com with the most subscribers. In this case "subscribe" means people who have signed up for an account with GoComics.com and than have clicked subscribed to individual comics so updates show up on their personalized GoComics.com portal. More of a "favorites" list then a full readership count.
I’m going to quibble with the statement that only one of the comics on the list is a "webcomic" — they’re all available on GoComics.com! I think the point Alan is really making is that only one of the comics, We The Robots, (and ironically WTRs is on indefinite hiatus as of this month) is not represented by a newspaper comics syndicate. I’ll also add that a full half of the list is represented by the newspaper syndicate Universal Press – which corporately is in the same ownership family as GoComics.com.