What happens when your google flight drops in price?

Am i entitled to the difference when flight drops, and if so, how to i get it?

clark mentioned it. it will search for the best flight in your area, money wise. and they do no time out on you, you can see a fare map

I usually buy 4 to 6 weeks out, and with Google flights, i can follow it. Does anyone know if american airlines will give you the lower rate if you already bought a ticket?