Over four years ago, I leapt on Mitch Kapor's fledgling service to sync browser bookmarks.
For some time during my Firefox days, I was a committed user, utilising the product to sync bookmarks (and later passwords) between at least three machines, and then different browser brands as support for them became available.
Then along came Chrome with its sync'ing capability. Chrome (for a number of reasons) became my primary browser on all my machines. Xmarks played its part for me when I moved to OS X to occasionally keep Chrome and Safari bookmarks sync'd, but but no longer was it in daily use.
Over the years, I watched with interest as Xmarks strived to build a scalable, sustainable business model, without success. Todays announcement bravely explains it all.
Rumour has it they came close to a deal with Google, and also that the code may now go Open Source.
Quoting Todd, who quotes Douglas, "..thanks for all the fish".