Adds highly customizable banning system to your store. You will be able to set ban rules for pesky customers: block names, emails like firstname.lastname@example.org, restrict addresses etc. Very easy to use, no special knowledge required, but some regex skills will be a plus.
Adds Birth Date field to all forms and a new total on checkout page with birthday discount. This is a fully automated modification with a lot of options to satisfy your needs. You don't have to do anything manually, even inform your customers about birthday discounts!
Exports your customers to Google Contacts. Especially useful, when you display your mobile phone as a main contact in your store, or at least have a smartphone with GMail account. Fully automatic, doesn't require any attention at all, works with unlimited number of contacts.
Allows you to set fee or discount for every customer group available. You may set a fee in percent to one group and discount in fixed value for another. You can also automatically move customers between groups, when their orders match (or don't) given criteria.
Assigns a unique reference ID (8-digit code) to all your customers and lets them share it to get a discount. Both referred customer and referrer can get a discount, when given criteria matched. A lot of options make Reference Program a very flexible solution to suit all your needs.