. opt in and opt out. Customers must be able to opt out of the system at any time and must be required to opt in at the start.
. age . the o2 scheme is not available to customers younger than age 16.
. data sharing. The targeted marketing is based-on information supplied by customer.
. frequency. because the sms is triggered by the customer moving into the geo-fenced area, there is a danger that the customer will be bombarded with messages as he or she walks up and down the street. the placecast american trial capped messages at one per every 48 hours and three per week. the o2 scheme limits the frequency of messages to one per day.