sponsored wedding
n. A wedding in which some or all of the costs, products, or services are provided by local businesses in exchange for exposure or publicity.
Examples
2001
For today's economy lesson we turn to Corinthia Batista, 22, and Faruq Robinson, 24, who were married Saturday in a traditional service followed by a lovely dinner for about 100 guests.

And everything, from her bra to his socks, was given by local shopkeepers — from Germantown to South Philadelphia and Pennsauken — in exchange for a promise of publicity. . . .

Batista and Robinson, who have daughters ages 4, 2, and 1, saw a rerun of that "Oprah" segment last year. They looked at each other and nodded. Yes, they decided, as if thinking in unison, they'd do it. Of course, few brides are as ambitious as Batista. She was determined to have the first fully sponsored wedding — an event that would cost the couple nothing at all. It took a year of extreme persistence [but] she persuaded approximately 35 business owners to give away goods and services valued at $40,000.
—Dianna Marder, “Nothing borrowed; everything begged,” The Philadelphia Inquirer, September 01, 2001
1995 (earliest)
Ah, a man for the '90s.

And one whose upcoming wedding on Feb 25 will be a splashy affair.

"The theme is pure, simple and white. The wedding is going to be televised, you know. It's a half-hour special. I thought it would be a good idea. We would like to celebrate with as many people as we can. I have fans who ask me "when' and "where', so this would be a good way to reach out to them"…and the sponsors.

A sponsored wedding?

"The wedding's not going to cost us anything. But, we've paid for the place. The dinner will be at Fort Canning, in the gardens. But I don't know how much the dinner will be. We're still looking for caterers to sponsor us. The sponsorship is not closed yet."
—Koh Boon Pin, “My Feb 25 wedding will be on TV,” The Straits Times (Singapore), February 03, 1995
Notes
In 1990, the average cost of a wedding was U.S.$15,000. By 2002, according to Conde Nast Bridal Group, that average had jumped to U.S.$22,360, a nearly 50 percent increase in just a dozen years. Special day or no special day, this is an absurd amount of money and, in 1999, Tom Anderson tried to do something about it. He's a Philadelphia entrepreneur who was getting married at the same time that he was trying to start a business. "It occurred to me that a startup company and a startup couple both need launch money," he told The New York Times in 2000. He must be quite a salesman because he eventually talked two dozen companies into paying for most of the wedding's princely U.S.$30,000 price tag. A newswire picked up the story and Mr. Anderson and his bride ended up on the "Oprah Winfrey Show." (Hence the "Oprah" reference in the first example citation.) What's next, I wonder? Nike swooshes on the bridal gown? Star Wars action figurines on the wedding cake?