Schwab's unit that offers services to independent advisers and other institutional businesses is the most profitable part of the company. San Francisco-based Schwab has about 6,000 independent advisers in its network.

"There has been a bit of a pack mentality with advisers," says Bernie Clark, head of Schwab Advisor Services. "When people started coming out and fostering growth in this industry, others saw it was possible and followed them."

Independent firms depend on their partnerships with Schwab and TD Ameritrade to succeed. Dorie Rosenband says she quit Smith Barney last year because she grew tired of its high-pressure sales culture and preferred to use her training as a certified financial planner to give advice. So she started a business in New York and Baltimore in 2009.

Trudge To Bathroom

Schwab helped Rosenband, 37, find office space and legal advisers and then hooked her up with Raylor Investments LLC, a Greenwich, Conn., consulting firm that screens investments for her clients. In exchange, Rosenband pays Schwab a fee for safekeeping her investors' money, executing trades and other transactions.

"You cannot underestimate the magnitude of setting up a new business," says Rosenband, whose firm oversees $50 million. "You're leaving a turnkey environment where you don't even realize what's being done for you."

Beacon Pointe, which manages $4 billion in assets, owes much of its recent expansion to TD Ameritrade. Beacon Pointe's 30 employees work in a ground-floor office decorated with undistinguished paintings by anonymous artists. To get to a bathroom, advisers have to either trudge down to the basement or take an elevator to the fourth floor. Beacon Pointe and TD Ameritrade formed an alliance in 2007: Beacon pays a fee for client trades through TD Ameritrade, and the discount brokerage funnels customers looking for advice to the small firm.

Returning Advisors

This year, the number of TD Ameritrade referrals is soaring, comprising 25% of Beacon's new clients through October. And Beacon is planning on acquiring an independent advisor with $120 million in assets in Scottsdale, Ariz., a first step in an expansion to get more business from TD Ameritrade branches across the country, says Matthew Cooper, Beacon's managing director.

Hopkins, the Beacon Pointe advisor, works a region between Orange County and Santa Barbara, talking with TD Ameritrade branch workers to find customers who need advice.

"They went to Ameritrade and thought they could do a self-directed approach but don't have the time or talent to do it," Hopkins says. "So Ameritrade recommends us."