This fictional character has an extensive fan base. There are more than one thousand videos made using this character in sites such as YouTube and a thousand more depicting his relationship with Sara Sidle. Of more than twenty-thousand fan fictionswritten about CSI in FanFiction.Net, more than half include Gil Grissom. There are also many other sites that update daily news about either Gil Grissom's status on CSI or William Petersen's activities in real life.
The GSR ("Grissom and Sara Romance"; the abbreviation is a pun on the term for gunshot residue, often mentioned in CSI) has accumulated an extensive fan base during the years with some sites getting thousands of viewers a week. Some fans consider this "ship" very similar to the one of Mulder and Scully in the X-Files. From the beginning, both shows showed a lot of chemistry between the two co-workers, leading viewers to assume that a relationship between the two would soon begin, when in fact it would take years of a platonic relationship and sexual tension for something to actually be seen, with both couples only sharing their first on-screen kiss in the eighth season of their respective shows.
In August 2007, upon rumors of Jorja Fox leaving the show, a grassroots campaign started. Thousands of fans that want to save "the GSR" and Jorja Fox, have donated to the cause, collecting over $8,000 for gifts and stunts targeted at CBS executives and CSIs producers and writers. Some of the stunts included a wedding cake delivery to Carol Mendelsohn, 192 chocolate-covered insects with the message "CSI Without Sara Bugs Us" to Naren Shankar and a plane flying several times over the Universal Studios of Los Angeles with a "Follow the evidence keep Jorja Fox on CSI" banner. Another side of the campaign includes mailing the show's producers a dollar, so as to save Fox's contract "one dollar at a time". As of October 16, according to the site's running tally, more than 20,000 letters with money or flyers have been mailed to the Universal Studios and to CBS headquarters in New York from forty-nine different countries since the campaign started on September 29.
On September 27, 2007, after CSI's season eight premiered, a miniature model of Gil Grissom's office (which he was seen building during season seven) was put up for auction on eBay. The auction ended on October 7 with the prop being sold for US$15,600, which CBS donated to the National CASA Association.
From: Wikipedia
