I worked for this Citi Cards for 1.5 years. I was in graudate school at the time and could not get my schedule changed. For that and other reasons, I left the company with 6 weeks notice. A few years later, I saw a hiring ad and asked to be rehired through the company's website. (Previous employees are asked to wait until someone reviews their employment records before an invitation is granted).
A woman from Citi Cards called me several days later, inviting me to take the employment test again because she had reviewed my past records with the company and said they "looked great". Obviously I thought of my employment with them as great, or else I would not have wasted my time attempting to reapply. I came in and took the test and did the process, taking a total of 3 hours and 35 minutes.
At the end, instead of giving me an interview like all the others who had passed the exam (of course I passed as well) she stated she would talk to my previous manager to see if I was eligible for rehire. I was a little shocked this was not taken care of BEFORE I spent 3 and a half hours there; the HR person told me this was Citi's policy. I saw this as suspicious, because it is remarkably inefficient.
Since they had asked me more than once to move up the management ladder while I was there (in graduate school I could not do this, because of time constraints), and had me train/mentor their new hires, I thought there would not be too much debate over my rehire status- yes or no. I even lost money for their benefit (commission) while I was not working with clients during newhire mentoring times. The Citi Cards HR person told me I would get a call from them confirming eligibility or denying it. It has been almost 3 months since then. I am told my previous manager has not responded to the HR emails and this is holding things up.
I recall this happening to a man I once worked with at Citi. He was a higher volume salesman and had better than average numbers, but they never got back to him about rehire status (neither confirming or denying after being invited to the over 3 hour test/application ordeal). I have been told this happens to many people and it is not a one-time-only fluke.
I also think they give no answer to folks in lieu of stating "no" due to employment law liability issues. As long as they are going to say no to you, they may as well pretend to offer you employment, collect info about you that they somewhere along the line profit from directly or indirectly, and limit employment law liability. It's mere speculation of course.
I can't imagine my new employer doing anything as rude as giving no answer after 3.5 hours of testing and a give-your-privacy-away application process.