T-Mobile Retail Sales Associate interview questions

I've completed two interviews with T-Mobile, both were super laid back and the managers made me feel at home. They asked typical interview questions.. Right after my second interview, i received an email request for my background check. Today (a week after I submitted the information) I got another email with a copy of my background check, which has cleared. My questions are... how long do they take to make an offer? Do they do background checks on everyone, or only the people they intend on hiring? Update-- I got the job! Quite excited to join this amazing company!

Called in to check on status of application and he told me to come in the same Friday for an interview. It's been about 3 weeks I now have a second interview. Hope I get it.