It's one of those great questions that can still stir up a lot of thought and debate. It certainly used to but I think the old walls have largely come down, we live in such a consumerised society now I don't think many fans care if their heroes are selling their name to a chocolate company that make kids fat. Infact so many of them do it now that you tend to think there's competition and status to be acquired to get advert 'gigs' now, and maybe until you've done one you haven't really made it yet, in many people's eyes.
And Gervais can afford not to do it can't he, as can Ben Elton, another who's postured over his refusal to 'sell out', the same man who jumps on every topical bandwagon going to produce a novel and has even dived into the highly commercial world of musical theatre and promoted both to the hilt on TV talk shows, which is self advetising. He's going to make profit from it, as he would by advertising someone else's product, there really isn't a lot of difference is there? They are all professional artists who perform for money. Has Gervais really done everything he's done for art, really? Night At The Museum franchise Ricky, remember that great piece of non-commercial art you were in?