Why did Verizon contract with S and R Communications?

Why did Verizon contract with S and R Communications to build those counties and not do it alone? 

While Verizon is in the process of phasing out its older 1X and 3G services those products are still very important.  At the time of establishment, Verizon decided it unwise to build a data only network and sell it to the general public when a completely separate company (U.S. Cellular/Sprint) handles the voice network.  Remember, not only does Verizon not own the typical operating frequencies, they did not own a single tower or fiber asset in any of the counties.

The enticement for S and R was the establishment of a new regional cellular carrier with nationwide roaming cababilities.