From the announcement:
Ten years ago we started On The Lamb. It was an excuse to make the games we wanted to play, and share them with the world. In those ten years we released three games, multiple books, and over a hundred miniatures. We're proud of our games and we're thankful for our family, friends, and fans for supporting us for the last decade.
Unfortunately, this is our goodbye. On The Lamb is closing down, the webstore will be shut off at the end of the year.