Just did it with SP's Price Protection on the SodaStream deal. I bought it originally for $80 from Amazon in March and now it was $63 through Staples - 20% from Dan's coupon code. Chase/Visa wouldn't take the last 20% because it was just a code, and the advertised 20% off on the site was already included in the $63.99 price, but they did refund me $15 so that's cool. Wasn't too difficult. I called up to get the form emailed to me and the rest of the process was done via email. Emailed them the completed form, screenshot of my Amazon invoice and screenshot of Staples page. Took 5 days from first email till they confirmed I was going to be refunded.