Like most things in business it's about customer/viewer outreach, advertisement, and money. Let's take You Tubers as an example. A You Tuber pays to promote their video so they gain more views; which gains an audience, then hopefully a fan base. People do not go around hoping to find an undiscovered blog that interests them. Even if they do and a blog has such a small fan base it will be extremely hard to find. It's not about what you're writing about, there's always another person that shares the same interest; but what good is it if they can't find your blog?
Honestly you need to pay to advertise your blog; be willing to invest! After you pay for your advertisement (or even pay to buy followers to gain reach; it's desperate, but it'll help people find your blog with same interests.) but back to advertisement. After you pay for your advertisement and get a good reach and base of followers/viewers then you start getting your money back. When you have a big enough fan base then you can start charging people to advertise on your blog (do NOT over advertise it; your viewers will draw away). Also when you are looking for people to advertise on your blog make sure the advertisements are relevant to your blog. Such as ads for baking, crafts, and photography so it relates to your viewers; not annoying ads like "go back to college for free" or crummy ads you see like that on websites.
After you start getting money from advertising it's time to keep your viewers and then also gain more viewers! When you start getting money from your advertisements then you have money to spend on whatever. Sometimes take some of that money and start doing promotions, like give aways. Put $300.00 of advertisement money you've earned towards a camera and start doing a free giveaway. For applicants to be eligible to win they must share the blog to as many people as possible with prof. What it does is makes your viewers happy and makes them feel like they are apart of the blog. At the same time it's sort of free advertisement so you get more viewers; more viewers meens more money you can get from ads.
Takes money to make money, and that's how the world works. If you don't want to do your blog for money then you will be probably at the same spot as today in the next few years; but probably with 4 more followers from doing follow for follow. It's honestly a one in a million chance you will gain a big free viewing base.