Google announced a partnership with XM Satellite Radio today, saying it would sell radio ads for the network's talk shows over its dMarc platform, an automated system that allows advertisers to place, schedule and track radio advertising.

The deal's roots are with last January's dMarc acquisition. The agreement adds new inventory for Google's growing advertising network, the source of their most successful revenue returns.

"Think of it as AdWords on the radio," Google spokesperson Brandon McCormick told internetnews.com.

If the thought is too abstract, wait until the fourth quarter of this year when it's a reality. McCormick said that's when Google will fully integrate dMarc and AdWords.

And that’s why Jupiter Research analyst David Card likes the news. It doesn't feel like a wet noodle thrown against a wall to see if it'll stick. "It seems like it's in their sweet spot, the advertising business," Card said.

"It expands their inventory, but it's not the same kind of inventory," Card said. "It won't appeal to the same kind of local advertiser who typically buys radio ads." But it might, he added, appeal to broad national advertisers.