Amount Sold
Sales, Proceeds
noun
The selling that you've raised (上げ) is the amount sold or number of sales. Think of a graph going upward, where it's rising as you sell more things.
The reading for 売 is the one you learned with 売る. The reading for 上げ is the same as the reading for 上げる, a word you learned previously. If you know those two separate things, you should be able to combine them into one awesome vocab thing.
だんだん売り上げが落ちてきた。
The sales have gradually declined.
DVDの売り上げはどうですか？
How's the DVD selling?
あの性差別の広告のせいで、売り上げが激減した。
Sales have decreased rapidly because of that sexist advertisement.