Hi everyone, first of thank you for looking at my post.

I am currently working on a project. A main website contain my company description, and information and links to 3 separate website / shopping cart (currently 3 maybe more later)

The 3 websites are different companies, selling different products. Which are linked to each other and link to my main site.

Now the question is, how do I setup it up so each site will benefit the most from each other for SEO?

Scenario 1

main website on main domain, and have 3 different website setup on sub domain and register 3 other domain name and forward them to the sub domain I create for them, and link each other.

(in these case isn't it the same by just creating different website than?)

Scenario 2

main website on root directory, than 3 companies setup on sub directory. Register 3 other Domain name and forward them to the sub directory.

(in this case, if I am correct I can promote 3 companies separately by their domain name and my main website will also benefits from the those 3 companies since their in sub directory spider will consider them as part of the main website right?)

Scenario 3

main website on main domain, 3 on sub domain, and promote them separately without giving them new domain, since their already on sub domain which is already consider as separate websites.

or each company in different domain.

(In this case which I believe none of the website benefits from each other, only benefits from links and not seo wise.)

Or is there other solutions or no solutions?

Thank you for your help.

I think they can, yes.

But, you will need to be tricky with it.

for example, I would use different anchor text for each link and I would make sure or try to make sure that they are similar in theme.

lastly, making sure they are on separate C class ranges would help push more juice.