In the bit of the business world I've seen, you try and maintain the relationships with people who pay you.
If an advertiser is paying to have their name linked on an article, I think it'll influence whether a writer includes some interesting but negative bit of information about the advertiser- regardless of any other involvement of the advertiser.
It's this subtle sort of interaction between a publisher, author, and advertiser that causes conflicts of interest without anyone trying to be sneaky or anything- just the perfectly natural instinct not to bite the hand that feeds you.
If an advertiser is paying to have their name linked on an article, I think it'll influence whether a writer includes some interesting but negative bit of information about the advertiser- regardless of any other involvement of the advertiser.
It's this subtle sort of interaction between a publisher, author, and advertiser that causes conflicts of interest without anyone trying to be sneaky or anything- just the perfectly natural instinct not to bite the hand that feeds you.