[rrrazdan]

Its just measuring the buzz, not if it's negative or positive. In any case people talking about your ad is a good thing. Even if they say bad things, it increases your brand recall. Reach is a reasonable proxy for comparison, if you assume that ratio of people who won't(or would) see the ad, to followers is pretty much the same across ads.

[fvryan]

Negative buzz was unlikely the goal of any of these ads. Depending on the brand it may matter more or less. Godaddy for instance has all the negative buzz they need.