Mac King's goofy charms are finally making him a more prominent headliner on the Strip. Photo by Christine H. Wetzel.

Well, here's a good problem to have.

Near the end of Mac King's show, the comedy magician leaves the Harrah's stage to seek out an audience recruit. The bit of business, it soon will be learned, involves shaking down the volunteer for a $100 bill and quite possibly burning it to bits.

You can understand it's important to ask if the guy has seen the show before. On this particular afternoon, the first one had.

And so had the second. "Three times," he said.

The third recruit was the charm for King, who last week marked the beginning of another charmed year -- number seven -- at Harrah's. During that time, he has moved upstairs from the 350-seat Improv comedy club to the 530-seat main showroom, while maintaining his reputation as the best entertainment bargain on the Strip.

More people now pay the full $21.95 ticket price, itself almost unmatched in the tourist corridor. But room guests, members of Harrah's players club and at certain times -- usually midweek during the school year -- sidewalk pedestrians greeted by showgirls all can access the show for the price of a $9.95 drink.

At those prices, you can't complain about the short pitch to buy magic kits and the like near the end.

King is contracted through 2011, and Harrah's now spends more money to promote him as a star presence. That in turn helps King's other ventures, such as his "Magic in a Minute" comic strip. He recently cut deals with AOL and the Applebee's restaurant chain for tie-in promotions.

All of it is made possible by a show that's as good as the incentives to go see it; one that's consistently funny, kid-friendly without being for kids, and punctuated by baffling magic tricks without having them be the sole focus of attention.

That role goes to King himself, whom more people know by now as the perpetual adolescent in the goofy plaid suit belonging more to Mark Twain's era of show business than the present. The same can be said of King's boyish delight in the simple appeal of a rope trick or dumb joke.

The suit, it turns out, serves as a comic commentary on all the things magicians are thought to have up their sleeves. It produces everything from twist ties to a box of cereal. In fact, everything is there for a reason. Repeat customers might notice how the jokes set up other jokes. It's not enough for King to pull a rock out of his shoe. He will pick it up later and shout, "Let's rock!"

Talk about low-tech. One of the show's biggest laughs comes from a mere facial expression, King's mugging when he dons his "cloak of invisibility" -- a yellow rain slicker -- to make an extended bit of transferring playing cards between a couple separated on opposite sides of the stage.

If you haven't seen King in the past couple of years, you'll get a big jolt out of the sole new segment, involving a camping tent, shadow puppets and proof that the magician's sense of humor isn't always as benign as his stage presence.

There may come a day when King must assess the need for a more extensive overhaul; a day that matinee competitor Rick Thomas may now be facing in his move to the locals-oriented Orleans.

But, King says, "I don't think we've reached everybody that would like my show." And his soaring attendance counts suggest he's only just now being recognized as a Las Vegas headliner.

He says the five audience volunteers recruited for each performance make each one different, because the recruits force different ad libs. On this day, the guy who finally supplied the $100 decided to improvise a little yelp, as though he'd been goosed from behind, while King was doing more mugging in a pretend trance.

Genuinely surprised, King laughingly asked, "What are you doing? Are you trying to make the show better?"

In two years, improv humor may be welcome if the show hasn't changed. But for the time being, King's doing just fine on his own.