Burglars like to break into houses that they have the easiest way in without getting caught.
So yes by having burglar alarm stickers and signs on your house can sometimes deter burglars who don't want to trip an alarm.
Sometimes burglars will still be so stupid that they'll take the chance of breaking into a home even if it does have burglar alarm stickers or even burglar alarms.
Take for example businesses that have alarms and cameras the burglars will still risk going into those places to steal.
They don't care if they get caught or not they just want to break in and steal stuff or money.
Even sometimes people will break into banks during the night and make off with money even though they know that alarms are on in the bank and they have cameras that will catch them.
So it's a good idea to have some burglar alarm stickers and signs but you should also have the actual alarm such as a Burglar Alarm through ADT or any other security place.