Years ago a friend of mine in SF started a review site, it gained traction by being fair and balanced. Once the website was a top 1000 site on the internet, my friend started to try and make money with advertising.
After a while, he grew dependent on a few select advertisers. Too dependent.
While he had built the business with integrity, at some point, he decided to start "helping" his advertisers get better reviews... to build goodwill and keep the checks coming.
This is fine, except it undermines the purpose of a review site. This is the time when his traffic plained out and started to decline.
I'm sure the same is happening here.