I quite like the advert, it for once tells you how it is that cats shouldn't be eating vegetables, they can't absorb the nutrients from them as well and they don't digest as well. Although then the advert at the end still tells you Iams has vegetable stuff in it which i think really contradicts the whole of the advert! I know a lot of cats will eat bits of all sorts that you offer them, one of my mothers cats steals envelopes out the recycling to lick the glue off of them (we do try to stop this) but even if they choose it, it doesn't mean it is good for them and so i don't see why cat food companies who are meant to have experts creating their diets still put them in.
I am not just getting this off wikipedia either i have studied both cat and dog nutrition to degree level and the theme the whole way through was dogs need both meat and veg but cats just need meat!