In an attempt to get a handle on what kind of people are out buying the iPad mini today, Piper Jaffray analyst Gene Munster has been out and about interviewing purchasers of the tablet.

As you might expect, more than half of the early mini adopters that he talked to already owned a larger iPad. But somewhat surprisingly, more than 75% of them plan on keeping it…

AppleInsider has Munster’s note to investors:

“iPad mini buyers surveyed by Piper Jaffray indicate more than half already have an iPad, and three quarters of them plan to keep their full size model alongside their new smaller model.”

Munster also noted that 72% of the folks he talked to that purchased a mini today did so because of its portability, reinforcing his firm’s belief that the tablet will sell well once consumers realize the benefits of the mini’s size and form factor.

We quoted Piper Jaffray yesterday as saying that it believed Apple would sell between 1 and 1.5 million units of the smaller tablet this weekend. But early sellouts of the mini beg to differ.

As for me, I sold my third generation iPad last week on eBay and pre-ordered the mini. I rarely used the bulky 10-inch tablet, and so I didn’t see much reason to keep it around.

What about you? Did you get an iPad mini today? Are you keeping your old iPad?