“YouTube celebrities” didn’t exist in 2007, at least not in the sense that they do in 2015.
You could move away from the mic to breathe or get bitten by your baby brother and get your 15 minutes, but it wasn’t something from which you could make a lucrative, full-time career. When YouTube was still the wild west, there were far more Tay Zondays than there were Grace Helbigs.
In the Dawn of the Age of Virality, perhaps the first football video to catapult its obscure subject to fame was “Cody Paul #5.