'volume'?

Hi,

Please have a look at this:

One CEO I know surrendered 8% of his volume when he raised prices, but the new prices stuck and the result was the security of improved cash flow

=> What do the bold parts mean? Do they mean:

- volume = number of goods/ amount of service sold to customer

- stuck = remained that high

by the way, can I say amount of goods? I know goods is a plural noun, but somehow I feel 'amount of goods' is not wrong...

Many thanks,

Nessie.