Contribution

[Xinfu]

Is it a correct sentence?

-Our publisher receives two contributions a week on average.

I have this question because I am not sure what counts as one contribution. For example, you put pieces of paper into one envelope, and you send it to the publisher, is it known as one contribution? But if this one single envelope contains 10 sheets of paper that are two essays, then are they known as two contributions? Then on the whole should I say one contribution or two contributions?

[Rusty]

The sentence is correct. The publisher is setting the criterion for what constitutes a contribution.
They could be counting content, envelopes or contributors. It's up to them, and it's up to you to determine what constitutes a contribution in their eyes.

[Xinfu]

Excellent answer. Thank you.