An Ovum person, a senior one, told me in all good faith that the only thing that really correlated with how near a supplier's position came to the top right corner on Gartner's Magic Quadrant was the size of their billing with Gartner. It's a bit of a common perception that 'some' if not 'many' research analysts are literally for hire, writing up the abilities, strategies and product strengths of the suppliers that engage them.
It's also very common that no-one is actually willing to stand up in public and say this. The Ovoid said it in confidence and mustn't be quoted. I've had IDC slagged off in the same way, ditto Aberdeen and the Forrester Group.
A storage supplier CEO said that he was absolutely certain Gartner would not take a supplier's money to say good things about them. He also said that he'd heard rumours that Steve Duplessie's Enterprise Strategy Group was for hire. He was adamant, forcefully so, that this was not true. There was a story he told me along the lines of a supplier getting a less than good review or report by ESG. The supplier said to ESG that they supposed they weren't spending enough money with them.
The CEO asserted that this was garbage. Steve Duplessie gets told all manner of marketing mellifuosities by suppliers and when he sees something that looks like b**s**t and smells like it too then that's what he thinks it is, no matter how many dollars the supplier in question is willing to spend with ESG.
Many journalists assume all research analysts are tarred with the same soiled brush. If no-one is willing to stand up in public and say 'research house X writes you up better if you pay them' and many people behind the scenes whisper what they assert are dirty little secrets, then how is a journalist or anyone else to judge what's true or not?
Was the Ovoid lying to me? Was the supplier CEO deluded?
What I do think is common sense is that if a supplier hires a research agency to evaluate its strategy or products and receives a bad report, one that points out inadequacies, then they will bury it. If said supplier receives a good report then they will publicise it. Have this happen enough times and we might think that said research agency only puts out good news for suppliers that pay it.
Where a research agency has a revenue stream from customers independent of suppliers then it can more readily distribute information that is not flattering to suppliers. The common sense thing is that he who pays the piper calls the tune to the extent that the music never gets played in public by the piper if the payee doesn't like the sound of it. That doesn't mean the piper isn't objective though.