I have seen many vendors hiring Sales Engineers or Principal Consultants based purely on technical aptitude, product knowledge, or even certifications, and this can be extremely hazardous to your revenue and Product Managers. One expert in Sales Engineering observes that roughly 30% of Sales Engineers / Principal Consultants do all the work. I've seen incredibly smart SEs asked to leave POCs, by the customer, causing irreparable damage! Think about how many times the customer is too polite to say "please leave", yet when you do finally leave, the damage is the same! Do your sales team and company a favor, hire a Sales Engineer / Principal Consultant who is as sales savvy as he/she is technical, the product knowledge will come quickly & easily. Plus, an "A+" SE / PC can go on calls alone when needed, increasing the AE(s) coverage which helps during crunch-times! *And a good mentor or Sr Principal Consultant is priceless.