Think about what your referral offer is. To do this, consider how much you spend on acquiring new customers. Ie you spent £5k last year on marketing and attracted 100 new customers, which is a CPA of £50 per customer. Or perhaps you spent £20k on Google ads and grew your database by 200 customers with a CPA of £100 per customer.
Next, consider the lifetime value of any new customer. If you serve this customer for at least 5 years after the installation, what will they be worth to your business?
We advise that a budget of between £50-£100 should be adequate to encourage your customers to remember you when somebody they know is looking for a new heating installation. Remember to build this offer into your pricing policy.