Happydale was the brainchild of Andrew Dabb, whom Seth met online when they were both looking to break into comics, Seth into illustrating, and Andrew into writing.  Andrew had the story, but Seth added his own sensibilities to it, so that the end result was a collaboration.  
Andrew once said of Seth: [Regarding] his work ethic; for one panel in Happydale, which showed the undercarriage of a truck, I can remember him telling me how he had actually spent a few hours laying under a truck and sketching. It was that kind of dedication and eye for detail that made Seth stand out.