Sorry, I couldn't think of any pictures to go with the blog post, so here's a rabbit looking at some maths on a nice, sunny day. (blog.folksy.com)
It may not be worth your time to open an account at a store you rarely visit, take a closer look at the math with cards at the stores you shop in frequently. (mybanktracker.com)
But take a quick look at the math first instead of assuming that the big final number is the way to go. (travelcodex.com)