To prime the populous for when other types of media manipulation occur - folk aren't going to dig into media manipulation if it's done by someone they like and never realize the sheer mass of it. But if it's by someone they don't...

If nothing else, Bloomberg's ad budget is a solid experiment for the impact of ad budgets on elections. I don't know how much of the transparency that seems to exist around what Bloomberg is doing is normal for campaigns, but that is also a plus.