I think a key point that is missed is the feedback cycle time. Real time bidding advertising has I believe a number of the listed concerns however the feedback

I think a key point that is missed is the feedback cycle time. Real time bidding advertising has I believe a number of the listed concerns however the feedback time is maybe hours at most and might be milliseconds. So the risk is in general a lot smaller and worst case you just lose some of the money you spent that day/week. With long term assets you could lose months worth of investments before your feedback loop fully kicks in.