Here is a scenario :
You don’t want to get a tattoo. Right? But today the tattoo shop has a free offer. So if you are an “idiot” you will quickly rush to the store and get a tattoo. Why? Because you think : This is a great offer and if I don’t do it today I will lose this chance.
But if the store didn’t offer any free tattoo, then I am sure you wouldn’t have gone to the tattoo store.
So the “Free” made a choice for you.
Don’t get fooled! And here is a solution that might work for you. If you read something like a free offer, put a price on it. And think if it is worth to do it for that much money.