Wai, Ronald
In Thailand, Ronald McDonald greets customers at the door with a smile and a gesture of respect called a wai. Although Ronald is richer, better known, and probably older than you (which in most cases would mean that you should greet him with a wai first), because you are a paying customer, in this case the reverse is true: Ronald wais you as you enter.
Note that I was really happy to see a US firm making cultural accommodations like this!
US business people, note how in the background the signs are in English and Thai. Thai people enjoy Anglo-American food, products, music, language, and general culture. It would be wise for us to reciprocate, not only because Thai culture has a lot to offer us, but also because of their strategic location, growing economy, and increasing interest in world affairs.