Learning to say no is the hardest and most valuable lesson you may learn as a business owner.
What often happens if you say yes to everyone, is your business might become fragmented. For example, our business is centered around WordPress. We get asked all the time if we can help with someones Shopify or Squarespace site. Even though these people would be new clients and added revenue to us, we politely say no to their business and guide them elsewhere.
Why refuse that business? Mainly because we drew our lines in the sand early. We decided what we say yes to and what we say no to from day one. While this may mean saying no to some new business, it makes it much more clear cut to us on when we say yes and when we say no.
If we said yes to everyone, our business gets fragmented. No longer are we a WordPress help team, we are just a web help team. We would have to train our teams on WordPress, Shopify, Squarespace, and every other platform we said yes to. That fragments our team and skills and over-complicates the ability to run the team effectively.
Once you learn to say no, you will often find it leads to many more clients in your niche saying yes.