Go with one domain, much easier for your SEO. Don´t do multiple domains or subdomains, it will cost you a lot more to get them ranked, even the subdomains route, since subdomains counts as separate domains in Googles eyes SEO wise.
I would go with multiple domains because I believe it is better not to keep all your eggs in one basket
yesterday I saw an interesting website. I never have seen such a site structure before.
It's a seo agency website /marketing.
So they have multiple segments and categories. But they were very creative.
having one domain name -their main site has a .com domain, and they have different content segments, like about news, dogital marketing, affiliate, seo...but with multiple domains like this:
I use my name Markus as example:
the main menu looks like this: hub- news- blog- tv click on it goes to the separate domain with their topics (categories)
and all separate domains all linked in the footer too+ th ecategories of each page, also domain .news showing the categories of the site .news in the footer, but linked to all other separate domains.
markus.com = main site
markus.hub
markus.news
markus.blog
markus.tv (they have selfhost videos and podcasts)
to have good niche/keyword organization so :
each separate domain has multiple categories "under menu link topics" all categories/topics are niche related.
markus.hub= here are guides about different topics
markus.news= digital marketing and IT news (blogging format)
markus.blog= blogging about different topics who have to do with the others
markus.tv = here are selfhost podcasts and videos
so each topic on each separate domain has a category page (they use tags) they have 3-4 topics (categories) on each domain
It's fascinating never have seen such a structure before.
I asked the owner via email and got fast and freindly response yesterday, he said he was first scary of setting up this structure, and he is happy to have success with, ranking for multiple keywords, and when your domain name has become known within time on the web, so when you type in google; markus or markus blog, google shows all other domains listed not only two. I think thi smethod is calling seo Dopmain diversity + topic categories.......
Today I will analyze it little bit deeper, type in markus.blog to see if google is showing multiple serp listings of their website topics two or more, category pages or tagged posts?
This is a very creative way to build you site deep and get it spread out on the web multiple times.
Yes thi smethod costs more money, you need 4-5 different webhostings, but you can start with cheap as $5-8 monthly for each domain, with more traffic scale up your webhositng plan.
His method punishes all lies that claim multiple domains are bad for seo, negative for ranking, you get google ban, blablablbalba....
None of that
Sop you can go this route or the other way building 2 category pages google will showing them, and building another similar domain name domain similar content with keyword cannibalization so you get multiple listings on google first spot like the big boys doing it; Zillo, Hearstmedia and all of them....
Happy Sunday !