No stickers on the car, I wasn't even supposed to see where they put it, but I watched the guy install it, so no deterant value
You get a key fob, which is more a return your keys if you loose them them advertising.
When I was getting a quote before I bought the car, one company (LV) would not insure me unless I had it fitted, and the one I went with gave me two quotes, one with and one without. I had to send them the invoice to prove I had fitted it after I bought the car.