It is an indelible image of the financial crisis: a bird's-eye view of the backyards of foreclosed houses, their in-ground pools festering with algae and mosquitoes. In Northern Virginia, Marcus Sheridan was in the financial storm.

By early 2009, his company, River Pools and Spas, a 20-employee installer of in-ground fiberglass pools in Virginia and Maryland, had a decline in orders from an average of six a month to barely two. That winter, four customers who had planned to install pools costing more than $50,000 each demanded their deposits back. For three consecutive weeks, the company overdrew its bank account.

Around this time, Mr. Sheridan began to overhaul his marketing. The company had been spending about $250,000 a year on radio, television and pay-per-click advertising. It would now cut the budget to about a tenth of that and focus on generating sales through informational blog posts and videos, what has become known as content marketing. But Mr. Sheridan took an unconventional approach to his content.

As a result, River Pools has recovered to exceed its peak pre-2007 revenue, and Mr. Sheridan, a 35-year-old father of four, has become something of a Web marketing guru.