You're apparently trying hard to demonstrate ignorance here. It's absurd, seriously, to assert that oversampling means they're "over spending." You clearly don't know what oversampling even IS much less why it might be useful.
If you want to know where in Texas to spend $10 million, are you going to do a statewide survey of 500 voters, which might tell you how you're doing in that giant state, or are you going to "oversample" the big media markets so you get a really good picture about what the voters are like there, how many are independent, what are their issues, etc. then TARGET the money and the issues covered in the ads to the voters in that market? If you're not a blithering moron, you do the latter.
First of all, I read the email AND the attachment, and if you read the attachment, it clearly outlines WHY they need oversampling - to figure out whether, and who, to target.