"The other big mistake I see entrepreneurs make is building a product for a customer they don't know well. That's why I always advise entrepreneurs to build a product for themselves--at least that way you ensure you've built something for a user you know intimately. All of the great tech companies of the past decade--Facebook, Twitter, Slack, Snapchat--were built by founders who were making products they wanted to use."
Equally, you can charge businesses to ‘claim’ their listing, a method used by many large directory sites like Google Business and Yelp. This involves companies paying to upgrade their listing and adding information such as their web address, social media links, images, and more. Other revenue streams include charging for ad space, adding affiliate links and even charging for services and products on your directory site.
"The way we’ve gotten around that is to always work with somebody on a project before we start handing over significant equity stakes or large sums of money. If the trial project goes well, then talk about expanding the scope of the relationship. Sam Altman from Y-Combinator once said something to the equivalent of 'a bad hire in the first few employees can be detrimental to a startup.' I've really taken that to heart in my business."