Graphic designers, please look over the edge of your screen every now and then. And people who hire them, please give graphic designers some information of the context in which the ad will be featured. Not knowing those circumstances might have a huge impact on how it will be seen. Or if it will be seen at all.
I just came across the above example where YouTube's "Skip Ad »" link pretty much covers up the company name of the advertiser. I guess that was probably not intended.
And it reminds me of when my brother (also a graphic designer) told me about a client who wanted a QR code on the bottom right side of a billboard that would be placed flush to the ground, forcing every passer-by who wanted to scan the QR code to get on their knees.