The point of my comment is partially tongue-in-cheek, because this is a problem Comcast can't solve, and they're setting themselves up for a rampage of angry people, as the amount of bandwidth being used for advertising increases every year.
But, since you brought it up, Comcast already examines your content. You are mistaken that net neutrality is broken if they filter advertising from your meter. Net neutrality is about not prioritizing or throttling responses to your request, not how Comcast bills you. And, for that matter, auto-play advertising is already worse for net neutrality than it would be for Comcast to categorize your surfing for billing purposes. Your internets are already being jammed and throttled by advertising video that in many cases is much larger than what you asked for.
If they are injecting ads (which I have seen through other providers, but I believe it wasn't related to Comcast) then your point is valid. At that point you are being delivered packets (large video-laden amounts) were not requested, and being charged for them. As a side note, I believe Verizon was doing this to mobile customers, not sure how it ended though.
So if Comcast bills you at double the rate for going to Facebook instead of Google+, that's consistent with net neutrality?
Am I understanding correctly that you want Comcast examining the content you are downloading and deciding whether it counts towards your usage or not? This sounds like the complete opposite of net neutrality.