The Manage Customers menu can display a list of all the customers or all the customers who bought a particular product. You can also display a comma (,) seperated email list of all the customers or customers of a particular product which can be used for bulk emailing to deliver important product related updates.

WP eStore Manage Customers Menu
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@Lynn, my guess is that the order verification failed at some stage… run the plugin in debug mode and it will reveal the exact cause of this. This page should help:
http://www.tipsandtricks-hq.com/ecommerce/how-to-test-the-wordpress-estore-to-make-sure-everything-is-working-properly-35
Remember you can keep the “Enable Debug” checkbox on in live mode.. it won’t affect anything and your customers won’t see anything different either.
Hi Amin, we have had two recent orders for books on our site and neither order/customer shows up in our manage customer screens. Any idea why they are not showing there?