I had been pinning only content closely related to my niche but when I added boards for other topics that would also be of interest to my niche, my results improved.
I started getting more followers, impressions, clicks, and saves.
If your Pinterest profile is all about sewing you don't want to add boards for golf because there's no guarantee that people interested in sewing are also interested in golf.
However, almost everyone on Pinterest is interested in food, home decor, and party ideas.
Add those kinds of boards to your profile, add pins, and you should see all of your numbers improve.
I'm using all of the above along with the steps in my new eBook.
As a result, I've seen a 19% increase in impressions of my published pins and a 47% increase for my saved pins in the past 30 days.