Duluth's Bayfront Blues Festival celebrates its 30th anniversary this weekend. Here are 10 things to know about the three-day event headlined this year by Don Bryant, William Bell and Bernard Allison.

1. A total of 30 acts will appear on two stages (one inside a tent) in Bayfront Park on Friday through Sunday. The music goes 11:30 a.m. to 9:30 p.m. the first two days, and ends at 8:15 p.m. on Sunday. For after-hours partyers, there is a late-night band in the tent from 9:45 to 11:15 p.m. on the first two days. The main stage features nationally known stars, while the tent tends to showcase regional performers. This year's tent lineup includes Dee Miller, Sena Ehrhardt and Cole Allen and Ross William Perry.

2. Attendance is about 7,000 to 8,000 per day. Each festivalgoer is allowed to bring in one lawn chair.

3. Bayfront Blues has a rare refund policy, in effect until July 31. Ticket holders can receive their money back or a ticket for the next year. About 100 people take advantage of the policy each year.

4. About 95 percent of the festgoers are returnees. "They've aged with me," said co-founder and owner Chris Mackey, who is about to turn 60. "However, the last two years we've noticed an influx of the 25- to 35-year-old crowd." At least 75 percent of the festgoers are from outside the Duluth area, Mackey pointed out.

5. Over the years, Bayfront has presented some of the biggest names in blues and R&B, including Buddy Guy, Koko Taylor, John Lee Hooker, Solomon Burke, Taj Mahal and Luther Allison. Bayfront never landed the late B.B. King, who usually did two concerts annually elsewhere in Minnesota.

6. Mackey's current wish list is Bonnie Raitt and Tedeschi Trucks Band, but they are not within the festival's budget, he said. And Keb Mo, another one who has gotten away, often performs at the Big Top Chautauqua in nearby Bayfield, Wis., so he's not usually available for Bayfront.

7. It costs about $200,000 to present the festival, including talent fees. Mackey has only one other full-time employee plus a half-dozen part-time workers. The only volunteers are the folks pouring the beer.

8. Souvenir sales are a key revenue generator for Bayfront. Sponsorships provide only 10 percent of the budget, and merchandise sales are a more significant revenue source, Mackey said.

9. While working for a Duluth hotel in 1987, Mackey tried to attract business on slow days by having Twin Cities blues bands perform in the hotel bar. The next year, he approached the Duluth visitors bureau and a local radio station about doing an outdoor blues festival. The first five years had free admission. Then Mackey bought out his partners and got more ambitious.

10. The keys to the success of the Bayfront Blues Festival are "loyalty combined with the location," Mackey said. "It's the location of coming up to Duluth that created the loyalty, but it's the loyalty that guarantees how much revenue to expect year to year."