The business of dog walking may be bigger than you think.

Back in the mid 1990s, Kristin Morrison started her own dog walking business called Woof! Pet Sitting Services.

Morrison ran the company for 18 years, and built up a crew of 35 employees before selling it in 2013. At the time of her company’s sale, she generated millions of dollars in revenue.

She declined to disclose the amount she received for Woof! Pet Sitting.

However, building it up from scratch wasn’t easy, Morrison explained to Yahoo Finance recently — and therein lies a lesson for other would-be entrepreneurs.

“In the beginning it was very slow. I did not know how to market, I didn’t know how to run a business,” she told YFi PM.

“I got books out of the library and I started studying, enrolled myself in my own business school at night,” Morrison added.

And it took years for her income to break the $100,000 barrier, which it did in 2000, and continued to rise for most of the following years.

Morrison says that when she started, her options for advertising were not as readily accessible as they are now. “I really utilized SEO, search engine optimization. So my website came up very high on the search engine,” she told Yahoo Finance.

Part of her initial struggle was proving that dog walking was a business. “When I started, people didn’t really know what dog walking was,” Morrison said.

Fast forward to 2019, and its become a bonafide market in its own right. The American Pet Products Association estimates that owners will spend over $75 billion on their pets this year in the United States.

As Woof! made money, Morrison said she was able to whittle her work days down to just three per week during her last decade running the business. She now runs Six-Figure Pet Business Academy, a business focused on coaching dog walking professionals.

Morrison added that things would have been easier for her if social media had been as ubiquitous as it is today.

“I absolutely would be using social media now. It’s so important. I mean, that is the way that people are finding out about different services,” she said.

“If you’re not using it as a business owner, you’re going to be left behind,” she added.