In the context of 'IT Consulting Companies,' which the blog post is about, it means that clients are paying a higher billable rate than for more 'junior' staff.
I have worked in consulting, and internally, the above was pretty-much our definition of "senior" that we used to determine who was billed out at "senior rates:" The engineers who also had customer-facing skills and coördination skills and understanding the customer's byzantine constraints skills and so forth.
Those who focused on just coding were billed out for less than those who spent time in meetings and writing words.
I was made "senior developer" three months out of university for exactly this reason. It helped that I also knew what I was doing, but the whole 1st dotcom bubble was a crazy time.
