In a soda market completely dominated by Coke and Pepsi, it wouldn't make much business sense to purchase Royal Crown Cola unless you also had plans to get your hands on Mountain Dew or Dr Pepper.
SoftBank would be crazy to pony up that kind of scratch for a perpetual place in the shadow of market leaders Verizon Wireless and AT&T. But the Sprint deal looks a whole lot more intriguing if you also have plans to add other carriers to the fold.
Or maybe even to acquire the No. 4 wireless service, T-Mobile USA, which is itself now gobbling up No. 5 MetroPCS.
"I don't think SoftBank will be content to remain in the No. 3 spot," said Julien Blin, directing analyst for consumer electronics at Infonetics Research in Silicon Valley. "They're going to want to move up to No. 2 or even No. 1."
To do that, he said, Sprint would have to use that huge cash infusion from SoftBank to go shopping for additional wireless spectrum, most likely by acquiring other service providers.
This could have profound ramifications for consumers. Short-term, a stronger Sprint would bolster wireless competition.
Longer term, however, further consolidation among wireless companies is almost inevitable, experts say. And with less competition comes the likelihood of higher prices and less incentive to innovate.
"There's a real danger that the four main companies — AT&T, Verizon, Sprint and T-Mobile — will coordinate their activities to extract as much money as possible from consumers," said Joel Kelsey, legislative director for the advocacy group Free Press.
Farfetched? Think about the behavior of the biggest banks or the biggest airlines. Robust competition often takes a back seat to copycat moves intended solely to maximize the amount of cash customers fork out for routine services.
With T-Mobile's deal for MetroPCS, one up-and-coming rival would be eliminated. SoftBank, on the other hand, wants a piece of the action. The only question is how big a piece.
SoftBank runs the third-largest wireless service in Japan. But that market is largely saturated and additional growth is limited.
SoftBank's chief executive, Masayoshi Son, 55, has made no secret of his desire to expand to the United States. A graduate of UC Berkeley, Son prides himself on being a decidedly un-Japanese corporate swashbuckler, willing to take risks that more conservative execs would shy away from.
When the iPhone first came out, Son didn't hesitate. He established SoftBank as the first wireless carrier in Japan to offer the device. He's now one of Japan's richest men, with a net worth of about $8 billion.
In 2010, Son unveiled a business plan not for the next quarter or the next year, but the next 300 years. Among other things, he said, SoftBank would invest in 5,000 companies by 2040.
By Son's reckoning, 99.98% of companies will cease to exist in their current form over the next three decades. SoftBank, he declared, will not be among the corporate roadkill.
"A person's life is over in 50, 100 years," Son said in announcing his 300-year plan. "But a company lives on through the people it is composed of, and SoftBank group has to survive even after I'm gone."
It would be naive to think that Son sees a multibillion-dollar investment to control Sprint as a final destination. Rather, it's a transit point to even grander ambitions.
Next up? The most likely play would be for SoftBank to seek full control of wireless broadband service provider Clearwire Corp. Sprint already owns about 49% of the company.
"Clearwire is very rich in spectrum," said Charles Golvin, principal analyst with Forrester Research. "That's definitely the other shoe waiting to drop."