Interlinking same niche

Hi.

I have a site in one niche that has huge searches per month and low competition(Keyword planner says that, not that easy, but not hard either)
Right now its serp is 3 for some high volume keywords.
But there are few more keywords that are even higher search volume.
I was wondering if i make 1 more site about same keywords and 2 more for the higher volume ones .
And interlink them, by creating a same footer for all the 4 different sites. (one site footer has other 3 sites links)
This should create a huge link juice and up my serps even more ?

I was thinking of using different seo services for different sites to see what works better.
BUT,
What if one of my sites get google penalized would it affect my other ones ?

Thanks

If you are running a white hat SEO operation, I only see massive benefits from inter linking your sites like that to create sort of what many refer to as a link wheel. Keep the positive ranking within your own network of sites.

But, when im using blackhat seo services from BST wich tend to get bitch slapped by google?
One get slapped, then all get slapped ?

How come i see this still happening, not between 4 sites, but 2.

Very interesting questions Mike420! I still see sites ranked in this way, but one day g00gle can consider them as private network. I had 12 domains interlinked in this way (link wheel) and the first 3 of them was deindexed - others with brutal drop in the traffic.

Why not doing silo structure on single domain instead spending much more money and time. Else I am in for testing this.

But linking like this should be fine??? first site => second site => third site => so on...