i saw lots of websites and online stores offering discounts if u buy through google checkout. $10 is not too much, but if your product is not more than $100 worth, than the 10% is good enough.
i placed an order last week and my package arrived sooner than i tought it could come. and i got the discount too.
if google will keep on offering discounts, i might start hunting for websites that work only with google checkout :)
and by the way, they just got their own blog.