Mays was found dead at his home Sunday morning and no foul play was suspected, Tampa police told news outlets. Autopsy results were expected Monday.
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"Although Billy lived a public life, we don't anticipate making any public statements over the next couple of days," Mays' wife, Deborah, said in a statement Sunday. "Our family asks that you respect our privacy during these difficult times."
The Discovery Channel issued a statement as well: "Everyone that knows him was aware of his larger-than-life personality, generosity and warmth," the statement read. "Billy was a pioneer in his field and helped many people fulfill their dreams. He will be greatly missed as a loyal and compassionate friend. Our deepest sympathies go out to his family at this time of incredible loss."
Mays had appeared on The Tonight Show with Conan O'Brien just last week with his Pitchmen partner, Anthony Sullivan.
His ads spawned a series of Internet remixes and parodies, and Mays himself lampooned his ads for ESPN 360.
Mays was on board a US Airways flight that blew out its front tires while landing at a Tampa airport on Saturday, MyFOXTampaBay.com reported.