Gold in IT niches?

We just released this year's Fastest-Growing Staffing Firms list.  In all, 44 firms made the cut, each generating compound annual organic growth of 15% or more between the years 2005 and 2009.

The most striking common denominator was IT.  Sixty-percent of these fast-growing firms said it was their top segment, typically generating a majority of their revenue.

Of course, the IT segment as a whole actually shrank during this period, declining from an aggregate market size of $17.4 billion in 2005 to $15.8 billion in 2009.

So how did these IT companies buck the broader trend?  And why was it IT companies that so commonly outperformed the average, and not firms in some other segment?

My guess is that it reflects the niche character of IT, in which firms often dominate some particular sub-skill, at least within a particular geography.

Interestingly, in last year's Fastest-Growing Staffing Firms list, we also saw IT firms dominate, again not because IT as a whole was outperforming but because it seemed to be the case that IT is more prone to staffing firm outliers.

In IT, more than any other segment, extremely high levels of growth are possible--monitoring and responding to what's really in demand seems to make all the difference.