Sorry, I'm a bit confused about this sentence. The roles your selling are the roles you're hiring for? I guess even if that's true I don't understand what you mean by selling roles before getting selective. Would love some clarification!
For instance on the challenges I liked that you put (largely paraphrased here) 'If you breeze through these we might want to talk to you.'. Having ploughed/struggledto set 5 now it's almost daunting to think people DO breeze through that. Granted, the stats you've published so far indicate those people are far and few between. It kind of puts you in your place, but the exciting part comes from knowing there's so damn much to learn still.