The story I've heard is that Canon rely on the people who don't bother to claim it back. I myself have recently bought the 7D mkii which is expensive for a 4 year old camera IMO, I paid around £1349 new and put a claim in for £120 cashback straight away. Only Canon are taking their sweet time about it and 3 weeks later I'm still waiting. I'm not one of those who complain but I feel like giving them a call about it. After all it would be unacceptable to buy a camera and pay them 3+ weeks later, and I really don't like double standards just because they're a company.