It is one of the most elusive and untapped consumer markets in the country, with an estimated annual spending power of nearly $452 billion. American Demographics, an authoritative voice on demographic trends, reports that the gay and lesbian market is colossal, and it is flexing its spending power like never before.

Thus, this month’s “From Gay to Z” Business and Marketing Exposition at the San Diego Marriott Hotel & Marina may be overdue. The April 24 event, presented by the Greater San Diego Business Association, will offer the first-ever forum for business owners to become acquainted with a historically neglected consumer group and an established chamber of commerce that they know little about.

The latter is the GSDBA, the third largest chamber in the country made up primarily of gay, lesbian, bisexual and transgender entrepreneurs. Founded in 1979, its membership has come to include 650 local businesses, with about 28 percent of them identified as “non-gay.”

Joyce Marieb, the GSDBA’s executive director, says large corporations have yet to market directly to the gay and lesbian sector. Some don’t know how. And others remain fearful. The purpose of the expo, she says, “isn’t to exploit the gay demographic, but rather make it known and understood to the community at large.”

Marieb credits the GSDBA’s recent growth spurt to a healthy operating budget that has spawned multiple network groups within the organization, as well as beefed up business mixers every six weeks at popular local venues. Just three years ago, the mixers attracted about 40 participants. Attendance today hovers at nearly 200. Additionally, the organization’s four networking circles are enjoying increased participation, ranging from 15 to 40 members per group.

“We’re seeing a lot of people get new clients from these events,” says Marieb. “It tells us that the mixers and network meetings are working.” Marieb also credits the chamber’s successes to growing outreach efforts that extend beyond the gay and lesbian community. “We always welcome new members from all demographics.”

Jeffrey M. Wergeles, GSDBA board president, describes the upcoming expo as an important component to the ongoing integration process. “San Diego has a thriving gay community that has been active in business and politics for years,” he says. “The future of this region is dependent upon a cohesive, interrelated citizenry and business community.”

Perhaps part of that vision has already taken root.

The 50 exhibitor booths allotted for the expo were sold out by mid-February and numerous sponsors from both in and outside the gay community are actively supporting the event. Sponsors include California Bank & Trust, Union Bank, Marketing Impressions, My Plumber, Audio Associates Inc., Scripps Ranch Home Care Inc., ClearView Eye and Laser Medical Center, Alvarado Institute of Skin Care and ROK Enterprises.

Media sponsors on board include San Diego Metropolitan along with San Diego Magazine, City Beat, Gay and Lesbian Times and Update.

When asked about risks mainstream businesses take when aligning with the gay and lesbian community, Cindy Lehman of California Bank & Trust says controversy tends to fade away quickly. “Customers in the past would ask us if we were doing the right thing,” referring to past marketing campaigns her branch launched to the gay community. “But from a business standpoint, it never hurt us in the long run. Everyone should want to do business with as many people as they can. And most businesses out there don’t realize that this community is very friendly and loyal.”

Lehman recalls receiving a $500,000 deposit at the bank’s Hillcrest branch from a customer she met while working her company’s booth at the San Diego Lesbian, Gay, Bisexual, Transgender Pride festival in Balboa Park. “This community refers business to me on a regular basis,” she says, adding that about 50 percent of her client base is gay.

Vicki Garcia of Marketing Impressions concurs: “Gay consumers are early adopters who have strong word-of-mouth clout in the mainstream market. They can help launch or legitimize a product or business.”

A small bevy of big-name companies can attest to those results over the past decade after creating ads that speak directly to gay audiences, either because of their placements in popular gay media or use of same-sex images. Companies like Absolut Vodka, Bridgestone/Firestone, Ford, Jaguar, Procter & Gamble, and Wells Fargo Bank are among those that realized they had more to gain than to lose by targeting gay consumers.

Yet many corporations, says Garcia, lack solid data on the market’s fundamentals, such as who they are, what they buy and how to reach them. “This is a demographic filled with hardworking individuals who buy homes, eat out frequently and spend regularly on health, fitness and financial services,” Garcia says. “The expo is designed to help marketers reach this audience and learn about the sensitivities that come with success.”

Three workshops will allow attendees to hear business leaders talk about their experiences in marketing to the gay community. Panelists will include Frank Lechner of Cush Autogroup, Michele Fortunati of My Plumber, Josh Jacobs of JW Window Fashions and David Cohn of Cohn Restaurant Group.

“Target marketing is always a very interesting subject,” says Cohn. “This is a subject that certainly needs to be addressed — and I’ve never seen any specific seminars on it before.”

The expo will feature a noon luncheon, followed by three panelist-led workshops beginning at 2:30 p.m. The schedule concludes with a no-host mixer from 5:30 to 7:30 p.m.

The cost is $35 for GSDBA members; $45 for guests. The cost for those wishing to attend the mixer and trade show only is $10 for members and $15 for guests. Registration is available on the day of the event, beginning at 11 a.m., or by calling (619) 296-4543.