I was in contact with an admin and was told to come to Staples headquarters. I was interviewed by four people total. They came into the conference two at a time as they had different roles.

Extensive. They have numerous interviews (3) for every person hired in the Home Office or the stores. They firmly believe past behaviour is the prime indicator to future. They use profiling excessively and want you to explain when you were required to challenge a previous employer but in actual fact they don't want you to challenge management after you are hired. They expect an excess amount of invested time into the interview process compared to the salary when hired.