When you auto-approve a member, they receive a notification via email like this:
Members will also see the list of all NetGalley clients who have auto-approved them on their Dashboard:
Plus, members can browse titles by publishers who have auto-approved them through a special link on the Find Titles page (once they're logged in), which looks like this:
By auto-approving members, you put your titles front and center as your most important members are browsing.