The effect of an ad posted on a niche related website [vs] an ad posted on a non related website.
Whenever someone sets up a website they usually want to get a flood of traffic to it so they can make a bunch of money. People always get drawn to paid advertising on PPC platforms and banner advertising on websites with a bunch of traffic since the website owner can capitalize off of those ad placements.
Putting your ad just anywhere you can find won't end well because you'll be wasting your money. Basically you'll be bundling your money up and throwing it into a fire pit while you cry So to avoid that, you'll need to advertise on niche related websites. This is because no one wants to watch you cry, but really it's because if you get your ad on a niche related website you'll have a huge spike in conversions compared to if you had an ad on a non related website.
Just think of it, if you loved snowboarding or skiing and went on your favorite winter sports blog and saw an ad for knitting tools, would you click through and purchase? Probably not. Now I'm not saying that the ad won't pull in some sales, because I've seen gramdas go skiing and I'm sure some of them like knitting. But the likely hood of actually breaking even on your ad placement is slim to none.
Getting your website up and running is just the tip of the iceberg. The parts you don't see are all the SEO campaigns, advertising, traffic and sales funnels behind the scenes which make a company great. Take your time when looking for the perfect ad placement and never jump the gun on this because you could be wasting your money. Do your due diligence and check traffic sources using moz, spyfu, semrush and any other source you can. If you're spending money on an ad placement, be sure it's going to convert well