With banks being derided as "too big to fail," it's easy to conclude there's little room for growth at the top of the financial food chain. But at least in Wells Fargo's (WFC -0.68%) case, such a conclusion doesn't account for the massive opportunity the California-based bank has to grow its credit card operations. As Motley Fool contributor John Maxfield discusses in the following video, it could double or triple this business over the upcoming years.