From the Model Mayhem FAQ:
What is a Certified Partner of Model Mayhem?
A Certified Partner is a 3rd party company that Model Mayhem has officially partnered with in order to provide our members with additional services. In some cases, these Certified Partners have special access to our systems (APIs) and may ask members to supply their log-in information in order to retrieve information like photos from their portfolio. Currently there are ONLY 3 Certified Partners of Model Mayhem -- Nextag (shopping), DriveThruSocial (personal websites), and EzPrints (comp cards). If you are ever asked for your personal MM information from someone, please check back here to see if they are a Certified Partner.