One common driver of headcount is enterprise sales and support. Once you charge at least $75,000/year, you need to put salespeople on planes, you need to provid

One common driver of headcount is enterprise sales and support. Once you charge at least $75,000/year, you need to put salespeople on planes, you need to provide actual tech support, and (unless you're disciplined and lucky) you end up with hundreds of features that are only used by one or two big customers each. Enterprise software is fundamentally a whole different beast. Customers will write big checks, but they expect a lot of different things in return for that money. I don't know whether this applies to DocuSign.