I'm with japanese on this one.
I can see the point about having all your eggs in the G basket, but for many site owners, like myself, it wasn't originally like that. When we started, there were about 10 worthwhile search engines, suppose Yahoo was the biggest, and we ranked OK/good on all of them. If you dropped on one of them, it was no big deal, you were ok on the others. Now, through no choice of mine, the big G has squeezed out all the others to the point where their results are irrelevant, and I now find myself in G's hands. I didn't ask them to take over the internet. Thank the other big G, we're not totally dependant, as we do traditional advertising etc, but G has got so dominant that any downward move hits me in the wallet. I was always aware that it was a bit of a free ride, getting any free advertising from organic search, but I didn't want, or expect it to end up being down to one SE