22 September 2026 · 6 min read · Oscar Markham
How much should a small Irish business spend on marketing?
Most advice on this answers with a percentage of turnover, which is useless when you are starting out and worse than useless when your margins are unusual. A better approach works from what a customer is actually worth to you.
Start from the value of a customer, not turnover
Work out two numbers. What is the average job worth in gross profit, not revenue? And how many jobs does a typical customer give you over a few years?
A plumber whose average job is €250 at 50% margin, and who keeps a customer for four jobs, has a customer worth around €500 in profit. A kitchen company with one €20,000 job at 30% has a customer worth €6,000 and will never see them again. Those two businesses should not be spending remotely similar amounts to acquire one.
Decide what you will pay for a customer
A reasonable starting point for a small business is paying no more than 15 to 20 percent of a customer's profit value to acquire them. Our plumber can pay up to about €100 for a new customer. The kitchen company can pay well over €1,000 and still be comfortably ahead.
This single number tells you far more than any percentage-of-turnover rule, and it stops the most common mistake in small business advertising: judging a campaign on cost per lead without ever working out what a lead is allowed to cost.
Then work backwards through the funnel
If you close one in four quotes, and one in three enquiries becomes a quote, then twelve enquiries make one customer. If a customer can cost €100, an enquiry can cost about €8.
That is your target cost per enquiry, and now you can judge any campaign in a fortnight rather than arguing about it for six months.
How much to start with
Enough to get roughly thirty enquiries a month, because below that the platforms cannot learn and you cannot tell signal from noise. For most Irish trades that is somewhere between €300 and €800 a month in ad spend.
Below about €200 a month, advertising rarely works well enough to judge. It is usually better to spend nothing and fix your Google Business Profile and website first — both of which are free and both of which make every euro you eventually spend go further.
What to ignore
Percentage-of-turnover rules, which assume every business has the same margins and the same repeat rate.
Anyone quoting a cost per lead before asking what a job is worth to you. They are selling volume, and volume is not the thing you need.
Written by Oscar Markham, founder of Dublin Growth Digital. We run lead generation for Irish estate agents and trades, reported every Friday in enquiries and booked work.