Intended to be a continuing series here at The WordPress Guy, this is Myth #1:
MYTH: Creating “Microsites” and using other domains I own that link or redirect back to my site will help my SEO.
Adding “microsites” and/or linking your owned “parked domains” will do very little to nothing for your SEO.
Search engines are pretty smart these days, smart enough to know who the registrant is for a domain and can see if it’s the same person as your primary domain. Changing or hiding domain registration may not work and can get you labeled as a spammer and blacklisted from search engines.
TRUTH: Regularly add meaningful and relevant content to your site. It’s how you get to the top!