One of my publishers
regularly sends out emails
giving updates on what sells
and what doesn’t sell.
If I have a choice
between two stories,
I’ll write the story
that will likely sell more first.
THAT is why
your sales team
and your product developers
should be in constant communication.
Product developers have the same choices.
They often have to make decisions
on which type of product
to focus on.
These decisions can be made
based on third party research
which may or may not be reliable
OR
it could be based on your actual sales.
I’d vote for the latter.