Coruscation

Hiring a full-time adviser is not unlike hiring a physical trainer -- someone who can teach you the proper diet and routine, and push you a little further than you may be willing to go on your own. "You should save to the point of discomfort and maybe beyond, and that is not something people will do unprompted," said Jim McCarthy, head of client advisory and retirement services at Morgan Stanley Smith Barney.

One reason some people are willing to pay a full-time planner is that they know they can call at any time without being on the clock. Mr. Richards, who runs the Behavior Gap site, said his clients had told him they called him first when they had a question or a calamity because they knew he wasn't "starting a stop watch."

"You don't fix emotional problems with logic, you fix them with trust," he said. "And that is really difficult to do, to build that over the phone if you aren't having an ongoing relationship."