This Town Already Learned What Happens When One Thing Carries Everything

Before it was a tourist stop, Tarpon Springs ran on one product. That story is the best lesson on customer concentration in Tampa Bay.

1905Greek immigrant John Cocoris introduces sponge diving to the area
1930sthe peak of prosperity for the Tarpon Springs sponge industry
1939disease hits the sponge beds and “substantially reduced the crop” for years

Source: Florida Historical Marker, Tarpon Springs Sponge Industry.

One product, one buyer market, one bad year. The town survived because it spread out. Today the Sponge Docks on Dodecanese Boulevard run on a mix of retail, food, and boat tours, a blend of heritage and hospitality, as the Tampa Bay Times put it. Your business works the same way. One big customer is the sponge bed. The mix is what keeps you open.

Where a Tarpon Springs owner can turn

City of Tarpon Springs. The city requires a local business tax receipt before you do business. New applications are done in person at City Hall through the Building Development Department, 727-942-5617, and renewals are due September 30. Source: City of Tarpon Springs, Business Licenses.

Florida SBDC at Pinellas County. No-cost consulting, listed through Pinellas County Economic Development.

Dr. Paul. The Tampa Bay business consultant page covers all twenty growth and survival questions. This one is number 97.

Four Ways to Work With Dr. Paul

02

Business Plan Writing

Need funding to add a second market or a new line? Dr. Paul writes the plan and the financials behind it.

Plan writing and prices →

03

Fractional CFO/COO

Track concentration every month with Dr. Paul, part time, so a slow drift toward one customer never sneaks up on you.

Fractional CFO and COO →

04

Small Business Education

Free guides on marketing, pricing, and finance for owners who learned the trade first and the business second.

Free guides →

How Much of Your Sales Does One Customer Carry?

Divide your biggest customer’s sales by your total sales for the last twelve months. Then find your row. These bands are Dr. Paul’s rule of thumb, not an industry law.

Top customer shareWhat it meansWhat to do
Under 10%Healthy. Losing them would hurt, not sink you.Keep measuring every quarter.
10% to 25%Exposed. One bad call could wipe out a season of profit.Write a plan to add customers. Get the relationship on paper.
25% to 50%Dependent. They set your prices, your schedule, and your stress level.Work the risk every month. Build cash reserves. Start the six steps below now.
Over 50%You own a job with one boss, not a business.Treat it as an emergency. Get help with the numbers this month.

Run it for your top three, too. If three customers are more than half your sales, you have the same problem in a different shape. Every Florida business consultant page on this site comes back to the same idea: no single thing should carry the whole business. The accounting and finance guides show you how to pull sales by customer from most bookkeeping software.

One Way to Add Customers: Sell to Pinellas County

If one customer carries too much of your sales, you need more customers, not a better relationship with the same one. In Pinellas, the county itself is a buyer with a program built for small firms.

Pinellas County SBE Program

A sheltered market for small firms

Pinellas County Economic Development describes its Small Business Enterprise program as a sheltered market that lets qualified small businesses bid on county purchases up to $150,000. Firms must be principally located in Pinellas, Hillsborough, Pasco, or Manatee County, and certification renews every three years.

Getting the notices

Register first, then watch

Bid alerts need county procurement registration, and the county says vendors must register in its free OpenGov portal to view active solicitations. The Tarpon Springs Chamber of Commerce, at 1 N. Pinellas Ave., is another place to meet local buyers.

Sources: Pinellas County Economic Development, Small Business Enterprise Program and Chambers of Commerce; Pinellas County, How to Do Business with Pinellas County. Checked 10/29/2026.

One warning. A public contract can grow fast and become the new giant on your sales list. Run the same customer concentration Tarpon Springs math on it that you ran on the old one, and keep growing the small accounts too.

The Day the Big Customer Leaves

A made-up Tarpon Springs supplier, rounded numbers. This is an illustration, not a real business.

Illustration · Before and after
Total yearly sales$600,000
Biggest customer, 35 percent of sales$210,000
What each sales dollar leaves after direct costs (40 percent)$0.40
Profit lost when that customer leaves: $210,000 x 0.40$84,000
Yearly profit before they left$60,000
Yearly profit after they left, if fixed costs stay the samea $24,000 loss

The sales drop 35 percent. The profit does not drop 35 percent. It disappears, because rent, insurance, trucks, and payroll do not shrink the day the customer leaves. That is why concentration is so dangerous: the loss lands on profit first.

Now flip it. If the same owner had grown everyone else enough that the big customer was 15 percent of sales, the same loss would cost a hard year, not the business.

Dr. Paul’s Insight: Your Quiet Customers Are Your Safety Net

Dr. Paul’s Insight · From Marketing for Small Businesses, Book 4, Chapter 1, “Anything for Anyone: A Raccoon’s Flyer” · Dr. Paul’s Fabled Forest Business School Series

“Which regulars?”

“The stationer at number four. Frankie’s, for the boxes and the ash. Alton’s, for the metal.” She shrugged. “Shop stuff. Weekly. They don’t call because they don’t have to. They’re the boring ones.”

Doctor Owl, who had been straightening the ash sacks in the truck so that their labels faced the same way, stopped, and looked at her over his spectacles.

“Say the last part again,” he said.

Dr. Paul’s take: The “boring ones” are the cure for concentration risk. Owners chase the big account because it is exciting, and the steady weekly customers get no attention because they never complain. Tarpon Springs owners serving the Sponge Docks crowd, local contractors, or a single big commercial account could all fall into the same trap. Spend a little of the energy you give the big customer on finding ten more of the quiet ones. The small business marketing guide shows you how to find and keep them.

Six Steps to Lower Your Customer Concentration

None of these require you to lose the big customer. All of them make losing the big customer survivable.

  1. Know your number every quarter

    Top customer share and top three share. Write it down. Watch the trend, not just the number.

  2. Get the big relationship on paper

    A written agreement with terms, notice periods, and pricing. Have an attorney review it. A handshake can end with a phone call.

  3. Meet more than one person there

    If your only contact leaves, the account may leave with them. Know the buyer, the boss, and whoever pays the invoices.

  4. Chase the quiet customers

    Find ten more customers like your steady small ones. The small business marketing guides walk you through it.

  5. Build a cash cushion

    Set aside enough to cover the fixed costs the big customer pays for, for a few months. Time to replace them is worth more than anything else.

  6. Plan it with someone outside the business

    A business consulting session turns the number into a monthly plan. It is the Plan step of Organize-Plan-Grow™.

Over 25 percent on one name? That is the call to make this week.Call or text (321) 948-9588 →

The Book on Knowing Who You Sell To

Marketing for Small Businesses book cover, Dr. Paul's Fabled Forest Business School Book 4

Dr. Paul’s Fabled Forest Business School Series · Book 4

Marketing for Small Businesses

Target market, positioning, and the customers who pay the bills without making noise, taught through one Fabled Forest owner per chapter. If your sales lean too hard on one name, the fix starts with knowing who else should be buying from you. Each chapter ends with a worksheet you can use the same day.

Get Book 4 on Amazon →

Customer Risk Questions Tarpon Springs Owners Ask

What is customer concentration?
Customer concentration is how much of your sales come from your biggest customers. If one customer is a large share of your revenue, your business depends on that customer’s decisions, budget, and mood. The higher the share, the bigger the risk if they leave.
How much of my revenue should one customer be?
There is no single rule for every industry. Dr. Paul’s rule of thumb: under 10 percent from any one customer is comfortable, 10 to 25 percent needs a plan, and over 25 percent is a risk you work on every month. Lenders and buyers will usually ask about it too.
Should I drop my biggest customer to lower the risk?
Almost never. The big customer is not the problem. The lack of other customers is. Keep serving them well, put the relationship on paper where you can, and grow the rest of the business until no single customer can sink it.
Does customer concentration affect what my business is worth?
Yes. A buyer sees a business that depends on one customer as riskier, and risk usually lowers the price or adds conditions like an earn-out. Spreading your sales out is one of the most direct ways to make a business easier to sell. Ask a valuation professional about your specific case.
Can Dr. Paul help a Tarpon Springs business by phone or video?
Yes. Dr. Paul works with Tarpon Springs and Pinellas County owners by phone and video from Deltona. Send your sales by customer for the last twelve months, and the first session starts with your real concentration number.

Know your number before your biggest customer changes theirs.

Dr. Paul Borosky, DBA, MBA

Business Consultant, Author & Educator | 14+ Years | 1,000+ Clients Served

DBA, National University MBA, Focus in Finance, Webster University Serving Tampa Bay from Deltona, FL

Dr. Paul Borosky, DBA, MBA is a business consultant, author, and educator, and the founder of Quality Business Plan. He works with Tarpon Springs and Tampa Bay owners on business planning, financial modeling, fractional CFO services, and the everyday problems of businesses that depend too much on their owners. He is the creator of Dr. Paul’s Organize-Plan-Grow™ Strategy, author of numerous published books on Amazon including Dr. Paul’s Fabled Forest Business School Series, and publisher of over 1,000 business-focused videos on YouTube. He has taught as an adjunct college instructor and teaches in Florida public schools.

14+
Years Experience
1,000+
Clients Served
$100M+
Projects Funded
1,000+
YouTube Videos

This page is for general educational purposes only. It is not legal, financial, tax, accounting, or other professional advice. The worked example uses an illustrative business with rounded figures. Local and historical facts are cited to their sources. The concentration bands are Dr. Paul’s rule of thumb, not an industry standard. The Fabled Forest and its characters are fictional. For decisions about your own business, consult a qualified professional.