Include free item

Will I be going againist Amazon policies if I add an extra item with each sell for free. For example I will use the brand Hard Rock. The stores are not in every state and im wanting to sell hard rock shirts and my town has a hard rock store. I want to sell a plain hard rock shirt but include a free a hard rock shirt with my town on it. By doing this unless another seller is in my same town I can’t get hijacked. Is this against any policy?