Diversity is Key
You hear it all the time - diversify, diversify, diversify. Whether you’re talking about investments or blogging / online income, diversification is absolutely critical to your long-term success. There will be ups and downs along the wrong - some areas will do great, while some will do poorly. Being diversified allows you to get through the tough times much less painfully.
Diversification also applies to your writing - yes I said it. If you write about the same topic day in, day out, every single day, for months ( or even years! ), you will get tired. You will get tired of writing, and your readers will get tired of reading. You need to inject something different from time to time - just to keep everyone on their toes. No one wants to read the same thing every day, and I know I sure as heck don’t want to write the same stuff every day. It’s just monotonous, and I can get that at my day job.
Sticking to your niche is great, and important to keep in mind. But don’t be afraid of going off-topic for a moment, just to take a break. You’ll feel better, and there’s a good chance your readers will appreciate it.