So yeah we were wonder why a lot of sale items where missing. I set it up to always show all items on sale and intuitively left “products per page” empty to show all of them but it seems it has a default value of 10… If the field is blank it should not limit the amount or give a note of the default value.
Additionally was there any pagination for this element planed offering this?
Hi Mike,
If the field is empty, the WordPress “Blog pages show at most” setting (wp-admin/options-reading.php) is used, which is probably set to 10 in your case. If you want to show all, enter -1 as the value.
We could insert a placeholder value as with the query loop’s posts per page, if that helps.
Pagination:
Ok thanks for the feedback. I didn’t know that Blog pages limits affects the products. It is set to 10 by default which explains my findings. I must say this isn’t optimal as products should never follow any blog limitations as on the user level they are not related. Some shops do have blogs, some don’t.
About
We could insert a placeholder value as with the query loop’s posts per page, if that helps.
I may not understand it correctly. You saying this is already possible or asking how a solution could be implemented?
From a WordPress perspective, “products” is a (custom) post type like any other and follows the settings for posts accordingly unless you set something else. How WordPress names this setting (“Blog pages…”) is not up to us 
Instead of showing an empty input field, we could show a greyed-out placeholder value that represents the “Blog pages show at most” settings, such as we do in the query loop “posts per page” settings:
