>If I want to buy tomatoes and a friend tells me a shop down the road has them on special offer, that's not collusion.We're not artificially suppressing the price of tomatoes.

You mixed up the analogy though. Rather it should be that tomato seller 1 talks to tomato seller 2 down the road and they agree to never charge less than x$ for 1 pound of tomatoes thus removing market forces and creating an artificial floor for tomato prices