Whenever a guest creates a reservation via eRes using either:

• a Group Code from the Groups Module area
• an eRes Promo Code from the Client Types area
• a Web Code from the Corporate Accounts area
• a Coupon Code from the Online Bookings Promotion area

A corresponding Source of Business is then created under System Configuration -> Property -> Source of Business when a guest makes a reservation (see below).  It will say "Web Reservation" and then the code the guest used (see below).

Therefore, you can get reports for Online Promotions by running any Source of Business related report in either RoomKey or BI.