Far more powerful than Islam is the power of Hollywood. All over the world, people see American TV -- and they want to be like us! For every Spanish speaking immigrant that enters the US, several Latin Americans learn English so they can enjoy our music. I know some Brazilians who traveled to the US to attend a concert. They hate American politics -- but love American music, and Americans!
Whatever the rough spots (some non-English speaking immigrants, some fundamentalist Muslims), the world is learning English and adapting modern Western tech culture. No need to bomb or bribe the world. Goodwill, peace, free trade -- these are our strongest assets.
I think the reason they sell so well is that people think they are a modern art Christmas tree. After all it says "Greetings" on the bottom. Now, if everyone who buys these would just put a tiny star on top, it would look just like one.