Recently Google Trends started showing data for websites. My sites weren’t there.
I was previously mistaken that this data came only from the Google toolbar. However, if you sign into your Google Analytics account you can add your data. (Obviously you have to be running it on your site)
Click on “Edit Account and Data Sharing Settings” and then check the 2 checkboxes. Previously I had “Anonymously with Google products and the benchmarking service” unchecked.