Boasting another 1.5 million subscriber quarter, Verizon had more than just customer gains to brag about today. It broached the 10% mark on revenues coming from data services, beating competitor Cingular and rising above the bar set by Sprint before its acquisition of Nextel last year.

Verizon Wireless reported $872 million in data revenues for the first quarter, which adds up to $5.60 per customer per month and 11.5% of all service revenues. Verizon Wireless said it had 26.1 million data customers--which includes all customers using SMS and Get It Now BREW services as well as V Cast and business users--each spending an average of $11.14 on their monthly bills on data services.

“The key to our success in wireless data is our commitment to investing in the network,” Verizon Communications Chief Financial Officer Doreen Toben said at Verizon’s earnings call today. “Verizon Wireless was the first carrier to build a nationwide broadband network, and we have the most experience in delivering broadband services.”

Verizon Wireless has credited much of its data growth to its V Cast consumer 3G service, though it doesn’t release any specific data on V Cast subscribers or revenue. But today Verizon did reveal that 6.2 million of its 50.7 million retail customers have EV-DO terminals. Many of those terminals, however, are data cards and EV-DO embedded laptops belonging to business customers, and an EV-DO phone doesn’t necessarily imply a V Cast subscription. In December, Verizon Wireless began selling the CDMA version of Motorola’s RAZR, one of the most sought-after phones in the market. The phone is EV-DO enabled, but only a portion of the customers buying it subscriber to the V Cast service.

Verizon Wireless added 1.7 million new subscribers in the first quarter, bringing its total customers to 53.0 million, 2.3 million of which were wholesale customers from resellers like its MVNO partner Amp’d Mobile. Verizon Wireless is now less than 3 million subscribers shy of the top U.S. carrier Cingular, which also added 1.7 million customers last quarter. Verizon Wireless posted service revenues $7.6 billion, up 16% year over year, but despite its increase in data ARPU, its overall ARPU continued its slide from the second quarter of 2005, landing at $48.67 per month, down 0.7% from year earlier and 1.4% from the fourth quarter. Overall ARPU may continue to fall as MVNOs like Amp’d increase their subscriber bases.