to tell you the truth search engine optimization services that costs no money could be of low quality, you could do it for a very small amount of money and with high quality and there are agencies that provide these services
There are a lot of "agencies" that charge money (lots of money sometimes) and provide low quality backlinks that have an obvious footprint that can be reported to Google or found by Google's algorithms and get your website penalized. Spending money doesn't mean you are getting higher quality than what is possible by yourself.
Well, I'll just say that I can't speak for porn or adult content because I've never done that niche. But you are right that in certain niches, especially content-driven niches, it is EXTREMELY helpful to have good quality content that gets an actual user base excited. Outside that, if you're trying to artificially rank a site that isn't in a niche where anybody is going to get excited about it you'll need to brute force your way in with some high quality links. At the very least it gets the ball rolling and allows you to get the eyeballs needed to get your site in front of the right people.
-ThopHayt
Well this gets to the root of the problem, and exactly one of my biggest points. People are trying to brute force their way into the top of the search engine rankings with low quality websites and content. That's pretty much the very goal of blackhat SEO. It's trying to take advantages of weaknesses in search engine ranking algorithms to get a site which should NOT be at the top of the rankings, to the top. When your content isn't very exciting, you need to be considered an authority on the subject to get links naturally. When you establish yourself as an authority, with relevant credentials or branding and content that makes people
believe you are an authority, it makes it more likely that people will naturally link back to you, or will accept guest posts from you where you can post original articles on the subject with links back to your site. At the end of the day, if you can produce a 1500 word original article at the level of a true authority on a subject, you can find people willing to post it on their websites for free, including some of the biggest authority sites in the world, with no payment required.
Here is an example list, that I am not going to check for complete accuracy, of high quality sites allowing guest posts, and I am sure almost all of them (if not all) allow a link back to the contributors website:
https://www.websitehostingrating.com/list-of-200-websites-that-accept-guest-posts/
If we look at the requirements for an SEMrush blog submission, they actually encourage you to include additional outbound links to other authority sites in your submission "Link to credible resources. if you want to ensure the reader understands the basics please link to credible resources."
That's where networking on Social Media and LinkedIn and niche relevant forums can be huge. Even if you aren't well know because of the traffic you receive, you can still brand yourself as an authority and market yourself to other people in your industry in these places, so when it comes time for them to build out a new high quality blog post, they are happy to link to you naturally. Of course, if your content is garbage, you can expect to be ignored.