After months of hand-wringing from Silicon Valley to Washington, the Federal Trade Commission earlier today unanimously approved Google's (Nasdaq: GOOG) $750 million acquisition of mobile ad network AdMob.

In the end, Apple (Nasdaq: AAPL) convinced the feds not to act. The Mac maker's iAd network, built on technology acquired in January from Quattro Wireless, has the chops to be a serious competitor to AdMob.

"As a result of Apple's entry (into the market), AdMob's success to date on the iPhone platform is unlikely to be an accurate predictor of AdMob's competitive significance going forward, whether AdMob is owned by Google or not," the FTC said in a statement.

After early losses, Google's shares entered midday rallying on the news, up more than 1% as of this writing. That's appropriate. Google needs ancillary ad markets -- namely, markets other than contextual Web search -- in order to grow its business. Mobile, and now TV, advertising are Google's biggest opportunities.

Worldwide, TV offers the largest potential slice of revenue pie. But now that consumers are buying more smartphones, mobile is attracting more attention, and more investment.

Verizon (NYSE: VZ) and Sprint Nextel (NYSE: S) expect to begin rolling out fourth-generation telecom networks this year capable of handling high volumes of complex data. AT&T (NYSE: T) joins the fray in 2011.

When these networks go live, users will find it easier to use location-based services and sponsors will have an easier time delivering location-aware ads. Google acquired AdMob to be the delivery boy for those pitches. Apple acquired Quattro Wireless for the same reason.

Before today, the FTC stood between these two like a referee holding back two fighters.

Now the feds have stepped out of the way. Let the brawl begin.

Was the FTC right to clear Google's AdMob acquisition? Discuss in the comments box below.

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Fool contributor Tim Beyers is a member of the Rule Breakers stock-picking team. He had stock and options positions in Apple and a stock position in Google at the time of publication. Check out Tim's portfolio holdings and Foolish writings, or connect with him on Twitter as @milehighfool. The Motley Fool is also on Twitter as @TheMotleyFool. The Fool's disclosure policy approved of this message.