To me it seems very likely that this is not wanted. Because with the uninitialized variable
$refererCampaignName Campaign data are always taken from
$visitorInformation has a campaign registered). Please take a look at the patch.
(In ) fixes #3550 referrerCampaignName typo; thanks Christian
oh very cool find, thanks so much, this bug was reported over the last months and I never found the cause, Cheers! Please keep patches like this coming ;-)
!^!^ .. I'm glad to be able to give something back