Small and medium business owners are so passionate about and close to their products, they can lack perspective.
Really, that is the biggest mistake they make overall. So find a way to make sure you bring the customer's viewpoint to the table.
That can be by hiring (full-time or as consultants) people who can challenge you and advocate for the customer. You should do customer research whether that is talking to customers, surveys, A/B testing, a whole host of tactics. We've even created a thought tool to help business owners and marketers take a more customer-first perspective. It's called the MECLABS Conversion Heuristic and it includes the elements that affect the probability of conversion. Many marketers and business owners post it on their cubicle or office wall, and use it as a customer-first gut check.
The next two mistakes are subsets of the first.
One is communicating without credibility.
When we have a value proposition workshop, there is sometimes frustration from the owners or marketers of, "But I'm saying all of these things on my website and in my marketing and it's not working." It's not enough to make a claim forecefully and emphatically. Customers won't believe it. State more facts and have less opinions. More nouns and less adjectives. More clarity and less rhetoric.
A great example was a small business we were working with that bragged on its website about how quick their product was to set up. They had specific statements that their product only took X minutes to set up while their competitor's product took X hours.
I (and probably most customers) thought, "Yeah right. If I go to the competitor's site, it probably says the same thing but in reverse." It turns out that data was from a respected third-party organization, but they didn't mention it on their website. Clearly adding the source can help increase credibility and therefore conversion.Here are some elements companies can use to communicate credibly: https://marketingexperiments.com/value-proposition/nine-credibility-elements
The other mistake is overlooking hidden value.
The only value that affects customers' purchase decisions is the value they perceive. While small companies make bold-faced claims they don't communicate credibly and oversell themselves, they also overlook hidden value and undersell themselves.
In that same example above, one of the reasons the company's product had a quicker installation was because they pre-configured it before it left the factory. The competitor had customers pre-configure it at home. But they never mentioned the pre-configuration on their website!
So it was hidden value
. Value they were creating, but value that the customer was unaware of so it had no impact on conversion.