How Do You define Gimmicky?

"A Series of Disappointments" A new book by Stephen Gill

This post is in response to a piece I read on another blog, 5b4 http://5b4.blogspot.com/ to be more precise. It was a review of a new book by British photographer Stephen Gill, http://www.stephengill.co.uk/ The article by jeff Ladd can be read here: http://5b4.blogspot.com/2008/05/series-of-disappointments-by-stephen.html It basically was less than sympathetic to this work and also some of Gill's other work. Here's the gist:

"For me Stephen Gill’s books have mostly amounted to illustrating well thought out and somewhat entertaining gimmicks that suit the idea of a book whether it is buying a cheap camera at a flea market and using it to photograph the flea market and surroundings (Hackney Wick) -- burying photographs of Hackney Wick in Hackney Wick and then burying the books too (Buried) -- photographing street workers wearing yellow safety jackets (Invisible) -- or photographing folded toilet paper (Anonymous Origami).
Christoph Schaden called Gill’s strategy ‘form follows technique follows topic.’ For me this naturally leads into the dangerous territory of gimmickry. To pile a lot of backstory about a camera bought for 50p from a man selling items out of his car boot in Hackney and then using that camera to photograph the place somehow makes these images more interesting? As much as Hackney Wick was touted as “one of the most important photo books,” do the owners of that book pull it frequently from their shelves for the actual pictures made with that 50p camera? I don’t know the answer obviously but I suspect that most of the copies need a good dusting".

Ladd, who's own work can be seen here:http://jeffreyladd.com/index.html appears to take a swipe at Gill's oeuvre implying, no actually saying that there is little substance, just novelty to his work.Now that's got me wondering how you would define a Gimmick? What's the difference between a brilliantly simple idea and a mere Gimmick when it comes to Art? Are say Bruce Gilden's pictures gimmick or technique? I don't know, I'm asking a question here as much as anything. I do feel that Jeff Ladd is just missing the point, (Not to mention the idiots who left comments on his blog about the post). I think Gill's work is original and exciting, Perhaps a little too English for Ladd's American sensibilities. I will again repeat the quote by Evan Williams, co-founder of twitter:
" The best ideas are always those that are obvious in retrospect. It's not about being clever, it's having the breakthrough to see the obvious thing that wasn't obvious to everybody"
And that for me, is the beauty of Gill's work.