If Chris Bliss is anywhere near as good in person as he is in this video, I'd hire him in a heartbeat. I'm not a big fan of juggling, but this is amazing. And then I watched this guy Jason, who does the same moves except he does it with five balls instead of the three Bliss uses (thanks to Seth Godin for the pointers).
As I watched Jason juggle, it was obvious that he is fantastic at what he does. But I wouldn't hire him for a corporate event. He's just not engaging. He looks alternatively show-offy, bored, and angry. Bliss seems totally engaged in what he's doing, excited about it, even a little worried. He pulls us into his experience through his showmanship and makes it ours. Jason seems to be doing it all for Jason.
Think about the difference, whether you're hiring an act to wow your attendees or lining up speakers—are they there to show off their brilliance, or to make an experience the audience can share and engage with? I'd take the latter any day.