When same-sex couples started saying "I do" across Florida the first week of January, travel agents and wedding planners started fielding calls from gay and lesbian couples within the Sunshine State and far beyond. With Florida already a popular choice for "destination weddings," the state's thriving tourism industry, and an LGBT scene in Miami and South Beach that draws vacationers from around the country, Florida stands to benefit from the same-sex wedding boom now, over the next three years, and well into the future.

More than $100 million this year
Weddings are big business in the U.S., generating about $51 billion per year. In 2015 alone, same-sex weddings of couples already living in Florida could add more than $116 million to the state's economy, according to the Williams Institute at the UCLA School of Law. That projection is based on estimated wedding-related costs like venue rentals and guest expenses such as hotel rooms and meals.

Miami-based LGBT travel expert Vicky Garcia, chief operating officer of Cruise Planners American Express Travel, says pent-up demand will drive the numbers. "Those who are marrying now are making a statement," she told The Motley Fool. "We've definitely seen a bump in phone calls in the past week."

Savvy tourism groups like the Greater Fort Lauderdale Convention and Visitors Bureau have been quick to cater to this new and eager market. In conjunction with Garcia's company, the bureau's new "Love is Love" promotion will culminate with a seaside wedding for 100 couples, gay and straight, on Feb. 5.

$182 million through 2017, maybe much more
Not everyone is in such a hurry. The average length of an engagement these days is about 14 months, which means many same-sex couples are planning now for Florida weddings in 2016 and 2017. The Williams Institute estimates a total of $182.2 million spent through 2017 on about 24,000 same-sex weddings of in-state couples.

The actual amount could be much higher. The Williams numbers are conservative, estimating roughly 24,300 Floridian gay and lesbian couples and their guests spending a total of $182.2 million. That comes out to an average of about $7,500 per wedding, including guest lodging and meals. But the national average cost for a wedding runs just over $28,000.

Not all same-sex ceremonies will be lavish events, but there's a perception in the travel industry that gay and lesbian couples spend more, on average, than straight couples on weddings and honeymoons. Garcia, who married her partner in New York, described her own decision to spend big: "We're both professionals and we have no kids. We're going to spend money on a great vacation, and if we have a reason to celebrate, even more so. I spent more than most heterosexual couples because, gosh, we deserved it."

And then there's the destination-wedding wild card. Estimates on the number of U.S. destination weddings vary from 16%-24% of all nuptials, generating $16 billion yearly. According to TheKnot.com, 18% of the nation's destination weddings happened in Florida in 2011, thanks to the state's sunny weather, tourist spots, and ports of departure for cruises. That figure could grow thanks to the same-sex ruling.

According to the Williams Institute, three of the five states that send the most visitors to Florida don't yet allow same-sex marriage. Those states -- Texas, Georgia, and Alabama -- are home to an estimated 74,000 same-sex couples. The report didn't run the numbers on out-of-state couples, but said that if "even a small number" of those couples tie the knot in the Sunshine State, it could have a "sizable impact" on Florida's economy. That's especially true because on average, destination wedding couples spend an estimated 30% more on their honeymoon than locally married couples.

"I think a lot of people are going to come here to get married before they go on a cruise, or out to the Keys, or to Disney," Garcia said, adding that travel agents are paying close attention. "We've been trying to get our franchisees to go after the LGBT market for the past two years. Two years ago, when we started training on it, 30 agents would show up. Last year, we had two back-to-back sessions with more than 150 agents."

Broader impact over the long term
The economic boost from same-sex marriages will go beyond venue bookings, florists, and honeymoon destinations. As LGBT couples find themselves on stable legal ground, they can make the kind of long-term spending, wealth-building, and family decisions that straight couples have long taken for granted.

"It's not just weddings, it's couples taking the next steps, starting families and businesses, making real estate purchases, doing estate planning," Garcia said. "People can put more firm plans in place for their relationships." That sort of long-term commitment may not be as bold and splashy as a beach wedding or a honeymoon cruise, but it can pay dividends for Florida's economy long after the ceremony is over.