[SEO/SEM] Network of websites for seo of one main domain

[johnny_d]

Let's say you have a website like this:

OpenSiteExplorer.org - Website X
Majestic.com - Website X
Ahrefs.com - Website X

Around 12,500 visitors a day, only around 4% from search.

It seems to be a very good and profitable website. Would it make sense to start working on a network of websites in order to increase rankings for the main domain. It seems like one of the things that could be done, website would be all very relevant to the main site.

What other things could be done with something like this, as far as search engine optimization? I understand that advice like this is not free, but maybe you can add something, I know quite a lot about it too, so we can discuss it here.

Possibly check quality and relevancy of all current links, and try to get more good ones, spread it out over a longer period of time. Good keyword research could be used too, possibly. There is quite a lot good books on Amazon for that.

[ITraffic]

i predict you are going to be planning and researching this "site" for the next three years. by that time the internet we know it will be radically changed and all your work will be wasted.

i recommend switching careers to a trade that is more perennial like plumbing as you will make more money than running a tube with sponsor clips and even transhuman god beings may still have to take a shit.

[SpyCam]

How are you going to make other websites increase rankings of the main site? Through link schemes? There is a high risk for being caught by Google for this, and all your network compromised and banned

[sinsan]

I will ignore the thread's title and respond to the question in the op

What other things could be done with something like this, as far as search engine optimization?

It's funny, because what I saw in those screenshots would be the results of what you are trying to do So building a network of websites just for the sake of optimizing the top 1, will result in what you already have.
I'm not trying to be ironic, it's my way of saying congrats, you might be (potentially) sitting on a gold mine. And with the ball in your yard, it's up to you to maximize it.
In terms of SEO, for a site with those kind of stats and performing so bad (se traffic), I think your main focus should be on-page optimization of your content.

I won't go into details because I don't know how your website is structured, what type of content it is, silo structure, url, categories, but the golden advice I am going to give you is: keyword research (optional) + write good (optimized) meta titles for every piece of content. Extra tip: don't go trying to rank for "porn", long tail will do just fine with your DA. good luck