Memorial Day weekend traditionally marks the official beginning of Maine’s tourist season. It also brings to the fore the traditional debates about the tourism “industry.”

What exactly is the tourism industry? Is it Maine’s largest? Do Portlanders visiting Eastport and Farmingtonians swimming at Old Orchard Beach count as tourists? Or are “real” tourists limited to those who come from “away?”

Where should we direct our tourism marketing dollars?

Is the “Vacationland” moniker on our license plates a help or a hindrance for our overall economic development?

These controversies are largely “inside baseball” arguments, important only to those involved in tax and regulatory proceedings in Augusta. More importantly, to the extent that they limit our public policy debates about the nature and importance of Maine’s image in the rest of the world, they serve no one’s purpose.

So, as we get ready for visitors to come to our beaches, lakes, parks, rivers, trails, restaurants, shops and the thousands of other places they find interesting, and as we search for ways to entice these visitors to return and bring others with them, I think our best frame of reference is the other form of travel that has become so prevalent — Web surfing.

Maine’s tourism promotion experts say that 80 percent of our tourists are repeat visitors. But how do they determine the first visit? And, more importantly, what share does that 80 percent make of all first visitors?

The social media analytics company Klout says that Justin Bieber is more influential than President Obama. How do they know?

By measuring first his virtual travel (where along the digital “road” he shows up) and second all the secondary travel — other people’s posts and tweets and blogs etc. — that his travel generates.

Klout and all its competitors are doing what we economists call impact analysis — how does one investment in an area generate a string of jobs in other businesses that are commercially linked to the first. Except Klout starts not with a physical investment but with a digital sighting.

Where does Justin Bieber appear along the digital network? How many links are there to be counted as a result of that appearance? Count ’em all up. Do the same for President Obama. And see who’s got more “Klout.”

The real (or at least broader) importance of tourism — both physical and virtual — for Maine is its clout.

What is the total impact of a first-time visitor? Does he/she come again? Stay longer? Influence friends and family? Rent a seasonal home? Buy a seasonal home? Retire to Maine? Bring a business to Maine? Start a business in Maine?

The anecdotal evidence of these indirect linkages is immense.

In just the past week I have encountered a financial manager who returned to Maine largely on the strength of his experience at Fryeburg Academy, a currency trader who retired to Portland at least in part on the strength of the city’s culinary and cultural attractions and an attorney whose 30-year career in Maine began because of the life-changing experience of a Maine youth summer camp.

Were these people tourists? Who cares?

The point is how did they make their first contact with Maine, and what can we learn from their experience to make it available to more people.

Is tourism Maine’s most important industry? Absolutely!

As the nation’s oldest and nearly slowest-growing state, we need more people — full-time people, seasonal people and visiting people.

But we need to broaden our definition of visitor to include the virtual kind.

We’ve become more savvy in telling our kids to watch what they put on social media because their digital first impression will precede their physical one.

We need to follow that advice as a state and focus more attention on what constitutes our own digital first impression and on finding out more about those who are receiving it.

Charles Lawton is senior economist for Planning Decisions, a public policy research firm. He can be reached at:

[email protected]