Google Analytics has a No-Override feature for traffic attribution, which is disabled by default: http://code.google.com/intl/en/apis/analytics/docs/gaJS/gaJSA

Google Analytics has a No-Override feature for traffic attribution, which is disabled by default: http://code.google.com/intl/en/apis/analytics/docs/gaJS/gaJSApiCampaignTracking.html#_gat.GA_Tracker_._setCampNOKey http://code.google.com/intl/en/apis/analytics/docs/gaJS/gaJS... I haven't worked with this setting myself so I can't say whether it works on all traffic sources or only campaigns. First Referrer information is stored in one of the GA cookies, so it's always available on the page, even if it's not getting passed to the GA servers. If you really wanted to get creative, you could yank it out of the cookie and throw it into a Custom Variable. This has the advantage of giving you First and Last Attribution, in different reports.