The sticker tells the thief you only have the factory alarm, which lacks a shock sensor.
The sticker tells him "Smash the window, but don't open the door"
A blinking LED, on the other hand, lets him know you installed an aftermarket alarm.
Most aftermarket alarms don't have a motion sensor, so most of the time, when they see a blinking LED, they won't smash the window, but unmount a glass pane, which takes more time than a quick grab.
Wanna hear a funny story?
Ten years ago, I had the "Pulse" Pink Floyd CD, which came with a blinking LED, inside my car.
The thief carefully unmounted a window glass pane, lowered the window, got inside the car, stole my stereo, got out and left.
The car was just a few feet from my bedroom window, and he did all this without waking me up.
This shows you that safety systems just slow them down, and make them choose an easier target.
Considering all this, I do have an security system WITH a Blinking LED on my 4Runner.