Health insurance giant UnitedHealth Group ( UNH) covers an astounding 78 million Americans. That big customer list endows UNH with some pretty nice benefits: It gives the firm a lot of leverage over medical providers, which in turn drives cost-conscious patients to turn to UNH's services. As secondary services become a bigger piece of UNH's revenue pie (especially after the effects of healthcare reform), that big client list is going to come in handy. >>5 Blue-Chip Stocks Ready for Buyers Despite the effects of so-called Obamacare, health insurance remains a lucrative business. And in fact, some facets of the latest round of healthcare reform actually boost UNH's bottom line, namely Medicaid expansions that let the firm get subsidies for even more patient care. UNH's scale is also important because it's one of just a few firms that can offer national presence. Huge employers that want to provide consistent insurance options will often find that UNH offers the easiest solution. Insurance is an asset-light business, and it's made even better by UNH's management unit that merely administers employers' self-funded health insurance programs. Financially, UNH is in good shape, with impressive enough free cash generation to warrant a dividend increase back in June. Investors should keep an eye on third-quarter earnings on Oct. 15.