What they should do is similar to the Tomy 'Capsule' series and include a small piece of track with each model, that way kids would be encouraged to buy more not only fro the models but also for the track that would come bundled with them. It could even just be used to display the models on if you were that way inclined, definitely a trick being missed either in that form or as a separate track pack 
Happily collecting things all my life... 