When you're a sales rep — or, as they prefer, "associate" — for USANA Health Sciences and you're attending the company's international convention, you'd better be ready to cheer a lot.

It's all part of the high-energy motivational presentation the Utah-based nutritional-products company make at the convention (going on this week at EnergySolutions Arena and the Salt Palace Convention Center). And it doesn't take a lot to get some of these people motivated.

Talk about new online sales tools, and there's a cheer. Show a parody TV ad featuring "the most interesting microbiologist in the world" (a spoof on the Dos Equis beer commercials), and there's a cheer. Show video of celebrities visiting USANA "gifting suites" at the Sundance Film Festival and the Golden Globes, and there are more cheers. Show the medal count of the U.S. Speedskating team (which USANA sponsors) at the Vancouver Winter Olympic Games, and there are big cheers.

But when you plop a real-life celebrity, in the flesh, right on the EnergySolutions Arena stage, the cheers go off the charts.

That was the case Friday morning, as actor-filmmaker Jason Priestley and his wife Naomi, took the stage to say hello to the USANA conventioneers.

The introduction was a little backhanded. Dan Macuga, USANA's vice-president for marketing and public relations, started his spiel about the Priestleys: "They wanted to be with us today, as our new celebrity influencers. But Jason was in Canada. ... They couldn't make it here."

Then the Priestleys stepped through a door and interrupted Macuga: "No, wait, Dan, we made it," Jason Priestley said, triggering a standing ovation.

Priestley kicked off his own sales pitch, by talking about how he talked to NHL trainers who recommended USANA vitamins. "We've been taking USANA vitamins for over five years now, and it's absolutely changed our lives," he said. "I never get sick, since I started taking them."

As for coming to the convention, Naomi chimed in, "We're part of the USANA family, Dan. How could we not be here?" More cheering.

And, like that, the Priestleys' brief appearance was over. But the sales pitch, and the cheers from the USANA faithful, kept going.