Yes, .5% isn't a lot, but thinking about what people spend on shopping, this could make a huge difference. If 100 people using this each spent $200 on Christmas gifts, that $100, which is enough to grow a set of cell cultures to test a drug or to study the molecular biology of a tumor type. This doesn't cost you anything, and you can only help!
CureSearch on Ebay! Anyone can list their items under the CureSearch donations page, and anywhere from 10 to 100% of the sale goes to CureSearch. http://givingworks.ebay.com/charity-auctions/charity/curesearch-for-children-s-cancer/14650/?favorite=siteadd&favnpid=14650