I find that it has the opposite effect. When I see something on the internet I want to buy, I add it to my wishlist instead of buying it. Then I forget about it until I look at my wishlist again, usually weeks later.
The best part is the added perspective and context the wishlist gives me. I can't buy that Old Smokey grill, for example, because the cast iron skillet is still in my wishlist and I want that more. And I didn't buy the skillet yesterday, so I probably won't buy it today -- sometimes status quo bias works in my favor.
I think in the short-term wishlists stop you buying things, but, because they persist you end up buying things that you would normally have forgotten about in the longer-term.
