I run about 7 websites (with plans for maybe 1 more). All of my websites contain original and quality content that I write myself, and I only do whitehat SEO. All get fairly decent rankings in the SERPS too (except for my newest ones).
Anyway, I have long since had a sidebar area called "My other websites" in which I have links to all 7 sites (with the anchor text of the site's domain and target keyword). I have this on each website I own
Since it is on the sidebar, it naturally shows up on everypage of every site I own. I figure this is okay since I am being upfront, and some users may be interested in my other sites (even if unrelated to the website from which they are referred).
Is this okay, even if some of the sites are unrelated? I have seen a Matt Cutts video where he says as long as it us under 10 websites linked together you should be okay.
Or is this a bad idea and could hurt my SEO?
I noticed other bigger sites do something similar (hotels, lifehacker, etc.)
Again, I do things whitehat only, and try to really build useful websites.