Google is out with a new self-driving car prototype, and it's fantastic. It has no brake pedals or steering wheels. To make it go, you just push a button. The contraption looks less like a conventional car than a space-age personal mobility vehicle. Eventually, Google says, it will build 100 of these things for a pilot project on California roads.

Watching the promo video, you might notice something else, too: Almost everyone appearing in it seems to be a retiree, or nearly so. There's Nick, the man who gives a chummy thumbs-up to the camera; Annie and Judy, who can't help but wave at everyone outside as they pass by; and Linda, who adorably prods her husband, Walt, over his inadequate turning skills.

Google unveiled the radical design for its own self-driving cars, which will have no steering wheel, pedals or brakes. (Google)

Google is known as a young, hip company. So what's it doing recruiting seniors to do its videos? Actually, it makes a lot of sense. Here's why: The elderly population in America is rich, vast and growing.

As the baby boomers reach their golden years, more of their children will need to consider taking away the car keys. By mid-century, one in five of us will be over 65 — that's up from just eight percent of the population in 1950.

But unlike their predecessors, this older cohort has tended to be more active, with some seniors launching "encore" careers that last long after they've officially retired. Rather than sitting around for a couple of decades, older Americans are feeling more energetic. It used to be that cutting off these older folks' access to a steering wheel was the only realistic option if their driving had become unsafe because of their age. Now, we might not have to. Google's self-driving car could get seniors out and about more. As a result, they might also earn more, spend more and give the rest of the economy a lift, too.

Google is targeting its cars to retirees for another reason: They've got the money. Boomers hold a vast share of the country's wealth, and, more importantly, they're willing to spend it.

"There is a bias to believe that older people spend less of what they have," according to Nielsen. "While this may have been true of the generations of older consumers that preceded the boomers, it simply does not apply to this generation."

Nielsen also finds boomers to be enamored of technology: They account for 41 percent of the people buying Macs and 40 percent of the wireless market. That's consistent with Jim Melin's experience. He's the president and chief executive of Air Force Village West, a retirement community in southern California that's home to mostly former military and business leaders.

"They've been innovators their whole lives," said Melin of the seniors in his community. "People are really interested in things that protect the environment around them. They come from a long generation of people that were taught to be frugal and not waste things. So whenever they see technology that they think is going to be helpful in being thrifty, they're all about that. That's what they grew up with."

Google is not the only company to see value in older customers. Earlier this year, Nintendo announced it was going to enter the health market in 2015. It's an important industry, particularly in Japan, where the population is growing older even faster than it is here in America.

So it makes total sense for Google to market its new car to older generations. Even Google exec Sergey Brin thinks so.

"The project is about changing the world for people who are not well-served by transportation today," Brin said at this week's Code Conference. "There are many people underserved by transportation today (the elderly, a lack of cabs and buses in some places). Look at people too young, old or disabled who can’t get around. It’s an issue and a real challenge for them."