Sales Volume is just one part of your Economic Model and works in concert with margins.
Sales volume is simply the number of units you sell in a specific period of time, say in a month.
You can be just as successful if you have a high-margin low-volume business as you could with a low-margin high-volume business.
A Lamborghini dealership can afford to sell only a few cars each month since their margins are high, but a Nissan dealer will have to sell lots of new cars since their margins are much smaller.
A software company with a successful product might experience a very high sales volume and high sales margins and reap huge rewards.
Given your margins, are your sales volumes sufficient to allow you to make a profit?