The ratio is much higher for software because it's an instant download.
Hardware is mostly used by businesses while software agents are mostly used by consumers and especially free members.
Because most people are becoming used to ordering online that waiting a day to a few days for most might not be a problem.
The Windows software is much more of a challenge to maintain across so many versions and so many possible combinations of packages installed on different PCs.
That said we do continue to try and find the elusive problem we seem to have with the Windows agent on some combinations of PCs and their installed software. However, this seems to be a rare problem as we've only heard about it a few times.