The hidden number key to Obamacare's success

Lots of Americans are signing up for health insurance outside the exchanges -- plans that are not offered on the federal and state marketplaces. They are adding to the overall enrollment figures and bolstering the share of young adults, who are particularly coveted because they're considered healthier and less costly. That's important for determining Obamacare's overall success since exchange enrollment is falling short of some projections, and those signing up are skewing older than expected. For instance, some 40% of those buying policies in the fourth quarter through eHealth, an online comparison shopping site that offers off-exchange plans, were between age 18 and 34.