Whenever I'm speaking with successful business owners, the conversation often veers toward the endgame. That is: What are you going to do after you cash out?

You've got some interesting choices. Do you give back to the community (start another business; become an angel investor)? Or do you reap your well-earned rewards and treat yourself to that Tesla or island getaway?

The decision isn't that simple, of course. But it's a decision that matters much more than you think. An entrepreneurial business community is an ecosystem of companies, employees, investors, and mentors. If successful business folks stay engaged after they strike it rich, the pool of investors and mentors stays fresh--and the next generation finds it easier to prosper.

I like to call this the "cycle of reinvestment."

It sounds great in theory. But the cycle doesn't always work. An acquired company could be forced to move. And, not infrequently, the founder may also leave town--or just stay put and disengage.

Here's how it ideally works: The founder launches a startup. The capital used to support growth--and the cash that goes along with it--flows into the community in the form of jobs and business opportunities. The founder sells out and is rewarded. Then, in most cases, he or she launches another business, becomes an investor in a startup, or maybe even both.

One region where entrepreneurs are building a system like this is in my own backyard: North Carolina's Research Triangle Park. The Durham-based Blackstone Entrepreneurs Network identifies serial entrepreneurs--folks who have run multiple businesses--and brings them together as a team to work with founders of young ventures. It keeps the gift giving, in other words.

But many business communities, unlike the RTP area, don't have a Blackstone to keep the cycle of reinvestment going strong. Local political leaders, though well meaning, can be clueless when it comes to keeping the cashed-out in the fold. And believe it or not, many former business owners can't figure out how to stay involved. So how do you make your postsale period work for you and your community? Some advice:

Coach: As an ex-business owner, you know markets, customers, and how to avoid most mistakes (you've made just about all of them). Make connections with companies that interest you and become an informal adviser. Incubators need experienced mentors as well.

Teach: Entrepreneurial programs have exploded--even at community colleges. Thus, business schools are looking for instructors with small-business experience. Nothing helps the "cycle" more than an influx of rookies. My class at the University of North Carolina, "Launching the Venture," has produced more than 100 real companies over the past 10 years.

Invest: For ventures you believe in, lead a capital round, form a syndicate, or introduce young founders to your contacts. In the Research Triangle, for instance, about 60 percent of the serial entrepreneurs and investors know one another; in Silicon Valley, the figure is much higher: almost 100 percent. That's a great network for young companies to tap. Join an angel group, or become a limited partner with an established venture fund in the early-stage market and help the firm do due diligence on the rising stars.

Network: Sponsor events to build the business network. Or just lend your expertise. Does building an entrepreneurial ecosystem really work? Well, I can tell you this from my research: Among "technology-intensive" regions, dealmaker-rich areas, such as the Valley and Boston, always perform better than other metropolitan areas.

The lesson for experienced entrepreneurs? Sell out. But for the sake of your community, keep buying in.