Even at their giddiest moments during the launch of the Shell MasterCard from Chemical Bank a year ago when executives from the companies vowed it would be the largest cobranded effort to date -- they didn't know how successful it would become.

By midyear, Chemical boasted 1.8 million Shell accounts, with $1.25 billion in balances.

Subscribe Now

Access to authoritative analysis and perspective and our data-driven report series.

14-Day Free Trial

No credit card required. Complete access to articles, breaking news and industry data.