Internet sales are grabbing an ever-increasing percentage of pool and spa industry market share.

Not only are shoppers purchasing more pool-related products via the Web, the number of online retailers serving the industry has also risen sharply in the past several years, experts say. Some estimate that Internet purchases of pool products have increased by as much as 50 percent in the past 12 months.

Meanwhile, the range of products and parts customers are willing to order online continues to broaden as well.

“We’ve seen the sales of the parts really skyrocket in the last 24 months, for both pools and spas,” said Daniel Harrison, president of Poolandspa.com Inc., an online retailer based in Las Vegas. “And more customers are using the Internet to buy products — like hot tubs — that very few people would’ve bought online three or four years ago.”

This pressure has pushed an increasing number of brick-and-mortar pool retailers to enter the online space. So far, these retailers are using a mixed bag of expansion strategies, from dipping their toe into e-commerce all the way to building massive Websites.

Most local pool retailers expanding into online sales have chosen to differentiate their brick-and-mortar presence from their Internet brand, and many are using separate DBAs for the businesses associated with their Websites.

“Our online business has a number of different partners and investors, and it was started after our brick-and-mortar store,” said Dennis Marunde, president of Pools.com and Arvidson Pools & Spas in Crystal Lake, Ill. “It uses a completely different name, and is marketed separately.”

Managerial reasons aside, many brick-and-mortar retailers are realizing that branding strategies developed in and for their local markets aren’t as well adapted for an Internet presence. While personal-name recognition and hometown atmosphere may create loyal customers for a physical store, these attributes often translate poorly to the online marketplace, where professionalism and authority typically make a better impression on potential consumers.

But less recognized, sources throughout the industry add, is the flipside of this trend toward online shopping. As a growing group of Internet-savvy customers realize they miss some benefits of buying locally — such as face-to-face interaction and instant access to purchases — many have begun using the Internet specifically to seek out local brick-and-mortar retailers, both for their expertise, and for purchases of products they want to use immediately.

“We’re seeing an increase in local customers who are purchasing on the Internet, and wanting to come to our brick-and-mortar headquarters to pick [their purchase] up,” Marunde said. “I’ve noticed that really taking off in the last 18 months.”

Marunde added that his company is currently working to set up a nationwide online purchase referral network, which will refer online shoppers to local merchants when they prefer to pick up a product locally.

If this indeed proves to be a growing consumer tendency, and if robust referral networks become a reality, brick-and-mortar retailers may have a new set of reasons to take heart.