You might say Alexa von Tobel is having a banner year. Hot on the heels of her New York Times bestseller Financially Fearless and her new satellite radio program Financially Fearless with Alexa von Tobel, the entrepreneur scored a fifth round of funding for her personal finance site, LearnVest Planning. Northwestern Mutual Capital led the round, supported by previous LearnVest investor Accel Partners, among others.

The $28 million cash infusion brings the New York City-based startup's total funding to more than $72 million. Last summer, LearnVest raised $16.5 million to scale its seven-step financial planning program, which von Tobel informally dubbed "Weight Watchers for your money."

In an interview with Inc., von Tobel said the funding opportunity simply presented itself. LearnVest, which aims to make financial planning available to people with moderate incomes, challenges the traditional planning establishment, some members of which deride the company as (in the New York Times' phrase)   "training wheels for know-nothing young adults." Competitors' harping aside, LearnVest is gaining meaningful traction, von Tobel said, and will continue to do so.

The site has become popular among affluent, well-educated people aged 25 to 55, von Tobel said, with the subscriber base of LearnVest's $19-per-month financial planning program growing by 284 percent over an annual period. The company's partnership with Putnam, a retirement plan provider, launched last December and has grown rapidly, she added. "Many companies come directly to us and buy plans for their employees." 

With the fresh round of funding, von Tobel said LearnVest can continue refining its apps for the iPhone and iPad, and build complementary apps for Android. The company also will continue to build out its online platform, which offers customers an analysis of their finances, and which will soon feature on-demand videos and live-streaming personal-finance courses.

According to von Tobel, the company is "hiring rapidly," especially in its New York headquarters and Arizona Expert Hub, where all its financial-planning experts are based. "We believe we are tackling the biggest problems for Americans in the most innovative way (software + planners + fee, no commission)," she added in a statement. "After we've built a solid foundation of tools and technologies to help solve these core financial problems, we firmly believe that there are many paths that LearnVest can take going forward to address customers' needs."