I don't think did as well as they or I hoped. I don't know if they did any marketing towards the Sci Fi community but that might have boosted sales if they didn't.
Marketing to the general public has always been a little weak on Lionel's part. The build-to-order model also makes it tricky and requires them to get way out ahead of it in trying to let a targeted audience know about these things. Personally, I think if the wider Trek community was aware of this product line, it would have been a good seller. Look at the Harry Potter Hogwarts sets and the Polar Express sets -- both are great sellers, but both had the advantage of being associated with trains, so they were easy to find by their respective fan bases. Trek isn't normally associated with trains, so the fan base is not likely to stumble upon this without some outside help (targeted advertising and press releases to target-oriented publications and chat/message boards, etc.). I suspect that this is also what is happening with the cancellation of recent horror-themed items. To slightly alter and paraphrase a line from Field of Dreams: if they don't know, they won't buy. And with the boatloads of other memorabilia out there, expecting someone to stumble upon your product is expecting too much.
Considering the popularity of the Hallmark Trek ornaments. and I know several people that have dedicated Star Trek Christmas trees full of these ornaments, a train to run around these trees would seem like a no-brainer. A one-time ad campaign could include flyers at Trek conventions, ads in Trek fan magazines, Trek comics, and online boards pointing to a web page explaining how they could get the sets and add-ons on pre-order and offer more details and artwork and perhaps ways for Trek memorabilia dealers to get in on the action. Once word gets out, and items start showing up for sale at conventions, fans (and dealers) would be looking for future releases without the need for further advertising. This is sort of what happened in the beer memorabilia world; although there was no ad campaign to start it that I know of, word got out -- my LHS has regular, non-train-person beer memorabilia collector customers that only order the various beer cars made by manufacturers, regardless of scale.
Andy