On Google's webmaster central official blog they announced they are adding META tag referrer support.
You can read the full blog post here: Upcoming changes in Google’s HTTP Referrer
The post was a bit technical, so we're going to break it down for you.
First, a little history. In October of 2011, Google made a change where once a user logged into Google, they would encrypt any searches you performed from that point on using SSL. SSL is the same technology bank's use to encrypt your session when you log into your bank's website.
This is a huge positive for the end-users. To understand why, many users may not realize that when you do a search on Google, click on a search engine listing result, whether it's an organic listing or paid, Google will pass the keyword you searched for to the third party website. When a user browses from one page to another, your browser (IE, Firefox, Chrome), will pass the last URL and certain data to the next website you visit via what is called the HTTP Referrer header field.
Here is a quote from WikiPedia's HTTP Referer page: "In the most common situation this means that when a user clicks a link in a web browser, the browser sends a request to the server holding the destination webpage. The request includes the referer field, which says the last page the user was on (the one where he/she clicked the link)."
This allows websites to aggregate the data and see where their traffic is coming from, the URL, and in the case of a Search Engine, what keyword they searched for.
Basically, Google's change on October 2011 broke that once they started using SSL and since it was encrypted, sites weren't able to recognize what keyword users searched for to find their website.
The bottom line for business owners that rely on website analytics for decision making, such as how effective their SEO campaigin is; either use Google Analytics which supports this recent change, or contact your website analytics provider or hosting company that provides analytics with your hosting account, and make sure they are going to support the Meta HTTP Referrer tag.