A while back I emailed Valvoline, Mobil, Pennzoil and Castrol. I asked each if there was any way that they could perhaps provide a few static cling oil change reminders. Shortly thereafter a box arrived from Mobil. Inside was about 20 reminders, 5 or 6 Mobil1 stickers and a very nice Mobil1 hat as well a letter thanking me for using their products and signed in ink by a rep. From Valvoline, they sent an envelope with a number of reminders, a few stickers and a letter thanking me. Pennzoil did not respond at all. Castrol sent me an email back saying that they don't do that sort of thing but perhaps I should go to an oil change location that uses Castrol products and maybe I could get some there. I had thought Castrol might be a little more considerate as I live in the same town that bp's North American headquarters are located in. None of this is significant but Mobil certainly seemed to show appreciation for a customer more than the others. It's always in the back of my mind when I'm in the motor oil aisle making a purchase.