I have Google Analytics on www.mysite.com. I don't want to count traffic that comes to www.mysite.com via a link on www.othersite.com. How do I set up the filter?
I thought I could just filter traffic from domain www.othersite.com, but that is not what that feature is for. It would be if I had GA on www.othersite.com and wanted to not count traffic on www.othersite.com.
The term you want is "referrer" - that's the what the other site is doing. Set up a GA filter based on Referrer.
However, you should know that this is unreliable. The other site could be referring visits that are not able to be identified as coming from that other site. The most common reason for this would be the other site's link being set up to open your site in a new browser window. Visitors using IE won't be identified as coming from that site.