The first interview is very short, about 5 minutes, seems like they only call you to make sure you are correctly dressed since they do not try to get much information. The second interview is an all day work shadowing with a sales representative, basically you get to see what would be your day to day agenda, note that sales representatives are told to be distant from the interviewee, at the end of the day, depending if they liked you or not they give a recommendation at the end of the day to the manager, the third interview is with the manager and he makes the final decision whether to hire you or not, the third interview is pretty unformal, it also lasts like 5 minutes and they just try to see if you would be committed to the job.