I'm not even sure if disguising promotions as popular trending content helps the product/service, whatever.
First you need actual content the people flock to, something creating a buzz, in order to have potential eyes exposed to ads/promotions. This particular ad, as well as a few others, combined, effectively pushed the actual content aside, meaning now there would be fewer potential eyes due to lack of interest.
If you were at a sporting event and a massive curtain fell that blocked the view of the action, for everyone, the stadium would clear. They'd leave and never come back because what's the point?
Other than that though, I really don't want to talk about this stuff. You're right though. If the ads had their own slots that were clearly marked and couldn't push content out of the way, I think that would be far more effective.