Sterlin' Bank...the One Customer [Only] Bank

I'm not a Bank person, probably because I believe the institution had the worst customer care (that is debatable once we consider MTN/Airtel/Glo/Etisalat). The first/last (and hopefully ONLY) time I was in WEMA Bank I had so much to say/write that a staff had to comment on my blog post. This time, someone requested I help deposit N1,000 into the daughter's account with Sterling Bank...the one customer bank. It was my first time of stepping into a branch. I have to mention, by the time I stepped out I was convinced they took their slogan "one customer bank" literally.
Location: Awolowo way, Ikeja.
As I stepped into the premises I noticed it had just a door into the building #ONE DOOR. I was also the only person about to get in and maybe that was the bank's idea- one customer at a time. It was weird because the banks I was familiar with experienced high influx of customers during the last opening hour of the day. The time was 10 minutes to 4 o'clock and I was the only one present. I stepped in and noticed the staff behind the counter were poorly dressed. Maybe because it was a Friday but Guarantee Trust Bank (GTB) staff dressed all days of the week as if they were going to a party. I got a deposit slip to fill and stayed on the queue which had only me on it #ONE CUSTOMER ON THE QUEUE. The guy and babe behind the counter were attending to customers #ONE GUY AND ONE BABE BEHIND THE COUNTER, I had to stand and just...look round. The bank looked like a waste of space. Spacious and not buzzing with activities. My thought had the idea of renting the space by the corner to make/sell my roasted plantain a.k.a Boli. I'll also sell recharge/call cards (everyone sells recharge/call cards). Like a minute later the floor manager (I think) began to shout "One Customer! One customer!" #SHOUT ONE CUSTOMER. The staff behind the counter began to hurry up. I was confused, probably it was a code to run or something. I took a step back and began to think of where to run if I see the staff leave the counter. The lady was the first to be through and called me to come forward. I later learnt from a staff they say/scream/shout "One customer!" when they wanted...sh!t, I've forgotten. The staff told me it had nothing to do with me.
I didn't write this to diss Sterling Bank, just don't understand why they decided to literally build a bank around a slogan. I mean, on the 19th of January 2012 their share price was N0.98 which was just two kobo less than #ONE NAIRA.