All this said, we should note that many boutiques are indeed small, ranging from upwards of 200 employees down to a single consultant. Often, boutique consulting firms grow from the expertise and client relationships of one to five founding partners, and unless it sells a consistently large flow of work, the firm has no compelling reason to grow quickly. Also, smaller boutiques can deliver services at lower costs than the larger consultancies because a smaller firm requires less overhead and less extra "capacity" (i.e., consultants), so their services might seem more attractive to prospective clients than those of the more expensive firms.
If you are especially interested in a particular industry or type of consulting problem, definitely do your homework on the outstanding boutiques in that field. If you find the right company to match your interests, you will spend all of your time doing the work you dreamt of, and that is a much harder goal to achieve within a more diverse consulting firm.
