Website Ideas and promotion methods?

I have experimented with a lot of methods to make few quick bucks online, like Fiverr, affiliate marketing with meathead's method and other random stuff here and there.
That was a long time ago, I wasn't really dedicated and had little or no money to invest. But now I have a steady job and willing to invest in IM for long-term.
First I thought of making a tech review website, hire writers and invest like 300-400$ every month for content writers, SEO, and SMM but turns out this niche is…

Website Ideas and promotion methods?