A friend of mine, Paul, did this in Zurich back in 2002. He saw that the Migros grocery franchise was giving 10x points for a week, some products were giving 10x points and his credit card was giving (I think) 10x points for the month. There was a special offer for miles-to-points at the time. So he put it all together for about 30 round-trips flights in Europe for a couple thousand bucks. At first they yelled at him, and then they relented.
When he told me about the idea, I just thought it was funny. When he told me he found a product cheap enough, and spelled it out, I immediately went to get the Migros point card, only to find out I had to wait a week for it, and the offers expired in the meantime. Damn.
Edit: I'm really fuzzy on the details. I'll ask him about it, if you want the exact specifics.
When he told me about the idea, I just thought it was funny. When he told me he found a product cheap enough, and spelled it out, I immediately went to get the Migros point card, only to find out I had to wait a week for it, and the offers expired in the meantime. Damn.
Edit: I'm really fuzzy on the details. I'll ask him about it, if you want the exact specifics.