,oRegistration for Sweepstakes or Contests. Occasionally, Back4Appmay run ,sweepstakes and contests. We ask those who enter in the sweepstakes or contests ,to provide contact information (e.g., an emailaddress). If you participate in a ,sweepstakes or contest, your contact information may be used to reach you about ,the sweepstakes or contest, and for other promotional, marketing and business ,purposes.