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Because it's a whole two months since they've published one of these things, Billboard just released its list of the highest-paid musicians of the last 12 months. And although it's topped by the usual suspects—Madonna and Bruce Springsteen always rule these lists—it contains a huge shocker by way of omission. Lady Gaga isn't among the Top 40 earners for the last 12 months.

Obviously, that's strange. Although her Born This Way Ball Tour just hit North America this year, the tour kicked off last April and she's played nearly 100 shows since then. And sure, her ticket prices might not run as high as Madonna's, but they're not exactly selling at clearance rates. You'd think that alone would put her above artists like Rush and Zac Brown Band, two bands that did make the list.  

But when you read the fine print on Billboard's post, her absence makes a little more sense. Part of the reason Gaga isn't on this list is due to Billboard's methodology. They're not including merchandise sales or sponsorships, which means the money she raked in from her perfume, concert t-shirts and that Pepsi marriage isn't being counted here. So don't worry about Gaga! She can more than afford that hip surgery

Still, when Billboard released their "Top 40 Money Makers of 2012" list, Gaga came in at No. 4. So either she made a bundle off of album and digital sales in early 2012 and stalled for the rest of the year, or they've changed their methodology in a big way. 

Regardless, this list is sure to validate Madonna fans and rile up Little Monsters. I'll throw the first shot: MADONNA RULEZ.