Robotics salespeople will have to be knowledgable about a wide range of topics. They will be like the pharmaceutical reps of days gone by where they were highly paid and well versed in specific hi tech pharmaceuticals etc.
One may not need an engineering degree from a university but certainly a background in robotics from a trade school or an online school could go a long way in the sales process.
Soft skills such as being a good communicator and having a good personality are sure wins in this job area.