We've made some changes to hopefully fix this, if it is still happening, please let us know what type of ad it is and any other details we can use to try to dig deeper.
It's hard to take a screenshot. I'll open a thread to read and as it is opening, it will suddenly jump to the App Store without me hitting anything. It's a minor annoyance - I don't even let it open whatever app they are selling.
I wonder if it's something on our end - I recently installed Candy Crush Saga. Fun game but obnoxious in how it tries to make money. I'd be happy paying $5 for them to leave me alone and let me play the game but that isn't an option.