And your 'c' key isn't intuitive either. Who sees a fullscreen ad and thinks 'Oh, I'll just press the C key, that'll get rid of it, right?'.
Getting in the way of content is the reason people use ad blockers. Your audience is aware of them and with intrusive and distracting things like this, usage is going to increase.
A 'sexy' interstitial is still an interstitial. At least others like Forbes have clear instructions.
With that said, realizing what's going on, moving my mouse, and waiting for the animation takes significantly more time, and cognitive load, than clicking through an interstitial.
I instinctively tried to scroll down past the ad, then noticed the article was bobbing on the right. I left without reading it. I shouldn't have to do a special action just to get to your content. Scrolling is intuitive, moving the mouse to the right side of the screen and waiting for an animation to move the content into view is not intuitive or user-friendly. I'm sure your advertisers love this though. I'd never heard of your site before today, you just lost a potential new reader because of this style of advertising.
Props for replying - communicating in the face of adversity isn't fun I know, so thank you for that!
I'll try to put my thoughts together in an email for you, but just incase I don't get around to it here's a seat-of-my-pants synopsis before I get into work.
Make the back-to-article functionality discoverable, tell your uses they need to hover over the article / press c / whatever to close the ad, tell people the content is over ----> there.
Techie audiences like here are more likely to not have their hands on a mouse, If I have to take my hands off the keyboard to click on the ad it's annoying also.
Think of you power users, I open a bunch of tabs then flick through them a bit later - This meant I missed the transition where it goes off to one side. I thought your website was a pop-under type exploit - not so hot! use the windows focus & blur events to activate your ad
Seeing the article for a second, then watching it fuck-off to never-never land is really annoying, It's like someone switching the TV off just after kick-off in a game of football.