Logos seem more important in the physical realm than the digital one. Great for advertizing on Bilbords, shirts, TV etc but meaningless when the goal is to click the link not remember the company.
There is still plenty of awareness generation on digital ads, especially desktop. Across I few products/brands I have monitored this effect. Typically I find on desktop display ads you will generate 2-4 additional visitors for every on ad click. Mobile interestingly is significantly less, more like an extra 0.5 visitors for each click generated.
More than logos, you need consistent and recognisable look and feel to an advert. This way the companies presence is communicated at a glace, which is what most people offer to digital ads.
