Businesses are being told they need to better understand how digital marketing works to avoid unscrupulous operators offering unrealistic returns on investment.
Search marketing company Insight Online said there were plenty of cowboys operating in the industry who prey on business customers who lack basic knowledge about how online marketing works.
Insight Online chief executive Kim Voon said digital marketing was a fundamental must-have for businesses, who probably needed to budget between $1000 and $3000 a month at a minimum.
However, he said businesses needed to do some due diligence before making that investment.
"The biggest advantage of digital marketing is that you know all the numbers. You know how many times people see your ad, click to go through to your website, how many people book a meeting with you through your website."
But he said it was just as important for a business to know how well their offline marketing efforts were working in order to make a fair comparison and set realistic expectations.
Mr Voon said companies should also take care when choosing an agency.
"Beware of someone that says that they can get you amazing results or promise you results. That's just not how marketing works," he said.
"But if someone takes time to teach you and work with you and explain how it's working, what you can expect, and the time that it will take, and you clearly understand why they're doing every action, then that's a good agency to work with."