I thought it might be interesting to look at the AmLaw 100 revenue in chart form to see what type of inferences might be drawn:

The most obvious point is simply the very long "tail" to the right.  Although the median firm's gross revenue is $362.5-million, nearly 60% of firms are under $400-million, and only 15 are above $800-million.  Apparently it's easy to be "relatively" big, but still extremely tough to be extremely big.