Mike, looking at their sourcecode.....
<title>CNC Robotics: Build Your Own Workshop Bot - Robotics Source Books</title>
<META NAME="description" content="Build Your Own Shopbot: Step-by-step, illustrated directions for designing, constructing, and testing a fully functional computer numerical control (CNC) robot. Robot mechanisms, mechanical devices, insectronics, amphibionics, pda robotics.">
<META NAME="keywords" content="robot, robot controllers, Build Your Own Workshop Bot, Geoff Williams, building robot drive trains, book, Michael Predko, Myke Predko, Predko, Doug Briney, Karl Williams, Gordon McComb, Yusuf Altintas, amphibionics, machinist handbook, insectronics, reference book, robotics, bot, shop bot, cnc machine, CNC Robotics, pda robotics, robot mechanisms, mechanical devices, illustrated, sourcebook, robot builders, manufacturing automation, illustrated directions, designing, constructing, testing, computer numerical control, CNC, robot, tips, tricks, pictoral help">
....it would appear that their use of Shopbot is meant as a Freudian slip. Notice that they did not list the joined word under keywords, nor was the b capitalised.
I wonder if the word ShopBot is registered as a trademark of ShopBot Tools, Inc.? The word is also used for "shopping robot" - something that crawls the web finding an item for which you are shopping.