Menu links between related sites controlled by same party - nofollow?

[centime]

I've got a couple of sites in related but distinct niches.
Some are interlinked.

I recently removed these links from one site(apparently penalised), and its rankings have slowly improved, even though I've done nothing else to the site as I was perplexed at its initial fall from grace.

Now, my analytics show that the sites definitely refer visitors to each other, but as they are sitewide, do they trigger a known Google penalty ?

Should one nofollow such links

[tedster]

I've got such links and never saw a penalty from it. However, each specific case could have other different factors at work.

If the links are important for your visitors (they seem to be) and if they were causing you ranking problems (your testing suggests this) - then sure, put the nofollow attribute into those links. It's better than losing the traffic by removing them altogether.

[edited by: tedster at 7:28 am (utc) on Aug. 20, 2009]

[CainIV]

Whether or not specific keyword phrases are used appears to be one of the defining factors. I too have sites, and link across when it suits the visitor as the sites are related.

I link using Example.com as opposed to keywords, and make sure that the area is labeled as 'sister sites' or 'our sites'

[Robert Charlton]

I've had problems from such linking... not for a while because I've taken pains to avoid the situation.

These were several instances of client "sister" sites for multiple but related brick and mortar divisions of the same enterprise, which had enough overlapping content to give the impression of overlapping keywords... and, most important, they had closely related backlink profiles. The sites had generally been promoted together (their print advertising was often sent out on the same flyer), and they were also hosted together, though not necessarily on the same class-C.

In such sister site situations, if there's a targeting overlap, and the linking and hosting profiles are similar enough, you may even have problems without cross-linking. In one case, I fixed the situation by moving hosting... in others, by building up separate backlink profiles.

Nav menu anchor text when there was cross-linking was for sister company names, not for keywords or urls, and the relationship (where there was cross-linking) was clearly identified.