Shazam, the mobile app and call-in service that helps users name songs, is taking further funding from Google (NSDQ: GOOG) and Amazon (NSDQ: AMZN) backer Kleiner Perkins Caufield and Byers, which is taking a stake, through its iFund, as it ramps up its paid app strategy.

The company isn’t detailing the amount. Its initial investmentf came at £11.5 million (now $18.3 million) from Acacia Capital and DN Capital. Times Online: “Of KPCB’s 520 investments, only three have been in Europe.”

Shazam says it’s now hit its target, revealed by CEO Andrew Fisher to us in May, of getting 50 million users by year’s end.

Before September, Shazam had amassed 20 million users through its phone service and ad hoc app downloads. But its iPhone app, included in Apple’s ads for the handset, gave it 15 million more between September and May alone, Fisher told us.

That’s propelled Shazam, which earns commission on songs users buy through links sent to retailers and is now profitable, toward its target. But the iPhone app remains free. Seeking a similar leg-up from the following wave of