If at first you don't succeed...
... fail, fail, fail again, if you're MS at least.
I doubt I'm the only site owner who recalls the last time MS revamped their search to unseat the Big G. They spent a mint yet ended up with an SE that produced results about as relevant as yahoo 6 or 7 years previously and a design that looked like 'Baby's first web project'. They made a lot of noise about how this was the Google killer, and we all watched our stats with bated breath to see if we now had to SEO for MS too. The needle didn't even flicker as MS share of referrals across my (Asian centric admittedly) sites declined steadily from 10pc to 5pc and beyond. It's now virtually a statistical irrelevance.
The problem MS (and the rest) have is that Google keep delivering results that are relevant and usuable without getting too much in anyone's face - on the surface at least. Until they start fucking up or get exposed as the evil empire they may well be, MS etc may as well not bother. Ironic really, as it was they who a generation earlier who condemned us all to an eternity of their dreadful soul-sapping OS being considered the only game in town.
Devil Bill, for missing the interweb bandwagon so loudly and publicly all those years ago