So with a maximum withdrawal of $200/wk, per card, it seems like you could realistically only be netting 400 miles a week (assuming 1 mile/dollar spent) per person. In all, 20,000 miles a year assuming you don't miss a week. Seems like an awful lot of work. However, if you can combine with bigcrumbs, you might actually not have to pay anything for them. Might make it worth it for some people.