Never, ever promote your best salesperson
Seems to me this is treating your best salesperson as a commodity; Deploy them where they're most effective and exploit their abilities to the full. But what about what they want? As with Ian Elliott, if you keep someone in a job they're great at, you may well get lots of benefit now but not have them at all within a year. Of course you shouldn't promote someone into a job for which they're not suited, but employment is a balance of mutual benefit; only as long as both sides are getting out more than they're putting in does the contract continue.
Therefore, for all I agree with Steve's conclusions - that you need to provide wider career options than just promotion to line management - I disagree with several aspects of the article that prompted Steve to write the editorial.
Semper in excretia, sumus solum profundum variat