Best Buy Canada

Why do these people bother asking me if they can "help me" when, obviously, they can't?

I took the bus to Best Buy today to see if I could find a few items.

The first item on my list was a video capture device for an iMac.
While I was scanning the shelf trying to find a Mac compatible device, I was approached and asked if I required any help.
I said, "yes, do you have anything that is Mac compatible?"
The sales clerk said, "oh, sorry... we don't have any in stock right now." He then walked away and started chatting to his friend/fellow sales associate. I excused myself and asked when they might get some Mac compatible video capture devices again. The other gentlemen said, "the Dazzle works on a Mac." I replied, "are you sure? I have a Dazzle I bought at least 5 years ago, and it is not Mac compatible." He assured me that the new ones work with a Mac. I was skeptical, and therefore didn't immediately decide to purchase the item. I decided instead to look for other items I need.

I headed to the camera department, being interested in alternative methods of powering my Canon Eos Rebel XTI (purchased from Best Buy). I didn't find much in the way of accessories for my camera, but one thing that caught my eye was a kit containing a "battery grip". I vaguely remembered reading something about a "battery grip" on the internet. I recalled that it was capable of powering the camera with AA batteries. I picked up the box to read the details, when I was immediately pounced upon by a sales clerk. "Can I help you?"
"Sure... is this battery grip the device that allows you to run the Rebel off AA batteries?" The guy looked puzzled, but then said, "No. you can't run a Canon rebel off AA batteries."
I asked him what the purpose of the battery grip was. His answer was "to hold the battery in place." I was very confused because my Rebel has no problem keeping its battery tightly nestled in its compartment. I expressed my doubts.
He said he would ask his friend what it was for. His friend's answer: "to help you keep a firmer grip on the camera".
Again, I was a bit incredulous.
He offered to open the box for me. I thought that was a little pointless, and asked if they had access to the internet instead, so that I might search for information about the battery grip.
He reluctantly allowed me to use the Google search engine on a computer.
A simple search led me to this:
"The Canon BG-E3 Battery Grip is designed specially for the EOS Digital Rebel XT camera. The BG-E3 holds up to two NB-2LH battery packs or six AA batteries to offer double-length shooting time..."

I turned around to let educate the clerk, but he had disappeared and was nowhere to be found.

I then went to the hard drive department, as I am possibly looking to acquire a 1 TB hard drive. As soon as I picked up a box to read the specs, I heard the familiar "can I help you?"
I said, "No. It's okay, thanks."

I continued trying to read the specs. "Can I help you?" another guy asked.
"No, thanks."

Third attempt at reading specs...
"Can I help you?"
I turned around to see the guy that had "helped me" with the Dazzle. By now I was growing impatient, and I couldn't contain my frustration I said, "No thanks... and you are the third person who has asked me if I need help in the last 30 seconds!" He replied "well, it's our job!" I said, "I understand, but I am having a hard time concentrating on reading this. If I need help, I will ask someone."

I wound up buying the Dazzle DVC100 DVD Recorder -- which I was assured would work on my Mac. I caught my bus back home (which took over an hour), and then set about installing my newly purchased item.

And guess what? That's right. The Dazzle DVC100 is NOT Mac compatible. Ha! What a surprise.

Could somebody please tell me what kind of "help" these sales clerks serve to provide?
If they don't know something, how hard is it to look for an answer on the internet?!