Robert_Charlton - 8:33 am on Jan 12, 2013 (gmt 0)

Independent link profile? i am not getting.

What I'm asking is whether the sites each have good backlinks from other sites, which are not connected with each other.

Do the sites each have independent backlinks... or are the backlinks from common sources? are you asking this in context to all the inbound links (backlinks) to both the sites? If yes, then both the sites have not too much backlinks, but some similar type like from directories or forum.

From your comments, it sounds like you don't have enough good links for you to be interlinking the sites as you are.

Guessing from what you've described, I'd say that chances are this interlinking could be a large enough percentage of the total inbound links for each site that it may well cause a link penalty. Your overall linking will probably look manipulative to Google.

For that reason, I'd recommend rel="nofollow" on the links between the sites (and I'm generally not very fond of using "nofollow".)