On a recent Tuesday morning, single mom Tammy DePew Smith woke up in her tidy Florida townhouse in time to shuttle her oldest daughter, a high school freshman, to the 6:11 a.m. bus. At 6:40 she was at the desk in her bedroom, starting her first shift of the day with LiveOps, a Santa Clara (Calif.) provider of call-center workers for everyone from Eastman Kodak (EK) and Pizza Hut (YUM) to infomercial behemoth Tristar Products. She's paid by the minute—25 cents—but only for the time she's actually on the phone with customers.

By 7:40, Smith had grossed $15. But there wasn't much time to reflect on her early morning productivity; the next child had to be roused from bed, fed, and put onto the school bus. Somehow she managed to squeeze three more shifts into her day, pausing only to homeschool her 7-year-old son, make dinner, and do the bedtime routine. "I tell my kids, unless somebody is bleeding or dying, don't mess with me."