Sitewide link to a sister site question

[bizzer]

I own two websites that are somewhat related. On Site A, in the nav bar below the header I had a link to Site B. The nav bar shows on all several hundred pages.  A few weeks ago I got nervous about this as I was doing some reading about sitewide links. Not exactly sure if they were a bad thing or not in this specific case, I decided to change the nav bar so that the link to Site B only showed up on Site A's home page.

Well, within a week or so my site started dropping from its long-held #1 position for its main, high-volume keyword, slipping a bit every few days. Today it is #4.

My question is, would the removal of the sitewide links and replacement of them with just a link on the homepage cause something like this to happen?  And, I'm thinking about putting the sidewide menu link back in -- is this a bad idea?

Note: the ranking on Site B is very important, with double the RPM of Site A.

[bizzer]

Thanks. I did make the links nofollow, as the purpose wasn't to pass rank, but to show the user a site that is also helpful to them, and related as well. (And I get nervous even making links nofollow, as it could be a signal to Google that I'm trying to page sculpt of something -- just can't win.)

Without giving away the exact sites, I'll try to describe with made-up site topics.  Let's say Site A is about how people can receive tax credits for installing solar in their home, and Site B is about saving money on electricity usage in the home.  Not the same products, but both interest the same user.  In my case, the sites are in the home telecommunications areas.

[ajfried]

I think I understood what you were asking and I thought you could extract some information from that video.

Let me try to clarify though.

Normally, site wide links are bad, even if its only one site to another and not the other way around. You could argue that they add value, which is why I linked to the above video, since it seems like that is a hard case to make (I don't know the site, I am just assuming).

So, this is really a bigger issue of value add. If it does add value, you could make a case that they should still be there.

That said, even in that situation where it does add value, the link should still probably be a no-follow since Google will likely interpret this as a spam signal or just simply trying to "beat" them at their game.

[bizzer]

Thanks for the response. But I'm not asking about interlinking sites. I'm asking about sitewide links from one site to another, not both ways.

[ajfried]

I remember watching something on this a while ago.

In general, it seems (from this webmaster help video ) that its relatively frowned upon. The only time that it might be ok is if its differnt country pages for the same site, but even that, it seems like its not the best idea.

That said, it's only one site, so it probably shouldn't cause too much damage to have left it.

Hope that helps a little.

watch?feature=player_embedded&v=JzaimchdNpM