People think it's another model of the PSP.  They have no idea that it's a different system.

Why not?  If people are dumb enough to think the Wii U is the same as the Wii,  then they're dumb enough to think the Vita is the same as the PSP.  The Vita actually looks the same as the PSP except analog stick instead of analog nub and there's two. 

Sony hasn't made a commercial to let people know that it's a different console.

This thread is brought to you by the letter s.  The letter s with a / in front of it.  /s.

And another one who knows the one and only truth.

Fixed.

indeed pspita or psp it is the same!!!

Sarcasm or not, people on my job still think the Wii U is a Wii and when I break out my Vita, they still call it a PSP. I just say "Yes. It is a PSP." I don't even try anymore.

It's not out of the question, but the name of the thing is quite different so I think most intelligent people could tell it apart, whereas the WiiU (in spite of looking at least a little different to the Wii) has such a similar name, hence the confusion

It has nothing to do with a lack of advertisement or a lack of games?

Damn! Talk about stubborn people! To be honest my friends used to call all the consoles from Nintendo, "the Nintendo". There is no name for them, just  "the Nintendo" xD.

The games don't compliment the Vita's abilities well. Vita tried too hard to be a pocket PS3 and for a handheld it's not the way to go. DS's two screens and stylus just made a variety of fun things possible.

Lol!  I still know people that call all video games "Nintendo", no matter what device they're on.  My mom was playing Candy Crush on the iPad and said she was "PLaying Nintendo".  She's not getting anything for Mother's Day.