A good case study is Nathan Barry and his SaaS, ConvertKit.

They increased their MRR from $5k / month to over $700,000 / month by changing their positioning.

Back in 2013 they initially positioned themselves as "email marketing for digital product businesses."

"We were just doing email marketing for whoever happened to be frustrated with MailChimp. That wasn't an effective marketing strategy."

In 2015 they changed their positioning. They started using the headline: "email marketing for professional bloggers."

Selecting a target market for your software product is one of the most important decisions you'll make. Evaluate each potential market on its ability to pay, its desire to pay, and its size.

(You can read the full case study here)