Companies live or die by their inclusion in that index. SEO is a nasty little cottage industry that benefits from the algorithmic monoculture in search.
On a somewhat related note, there is only one display advertising program that anyone cares about.
If you get banned from Adsense because a competitor hammered an ad on your site, say - you're out. Forever. With no explanation from Google. Just an unhelpful "you've violated one of our policies but we can't tell you which one" stock email.
I've been there. I tried the (token) appeal system, and failed. It's hard to appeal when you don't know what you've done wrong. Google won't tell you what you've done wrong because it might reveal part of their algo and thus help the bad guys.
So I forlornly moved on. Amazon ads are perhaps the next most profitable display ads for me - they generate less than 10% of the revenue that Adsense did.
I love Google for their excellent free services. However, I've come to depend on them, and that's dangerous because they're so ubiquitous, yet owned by a single entity with a single culture.
As geeks I feel we need to re-examine our relationship with Google.
Android fanboys and "Google Openness believers" could sleepwalk us all into the next dark "Microsoft" chapter.