Amazon's Kindle Fire falls short of the iPad in a satisfaction survey but has some big upsides, said market researcher Changewave Research in a note released Thursday.

The Kindle Fire has become surprisingly popular because it's affordable yet versatile for its price. And the numbers bear this out.

Bob O'Donnell of IDC told CNET this week that he believes Amazon shipped just under five million units in the latest quarter. "That's huge. Remember they didn't ship until early November so that's essentially two months," O'Donnell said. (Amazon does not reveal exact numbers.)

So, what do all of these users like about the Fire? Cost overwhelming but the screen and ease of use rank up there too (see chart below).

That said, it isn't the iPad's equal in overall satisfaction rating.

"While the 54 percent Very Satisfied rating for the Kindle Fire is considerably below the 74 percent rating of the industry leading Apple iPad, it is higher than the 49 percent average rating for all of the other tablet devices combined," Changewave said.

And what do users dislike about the Fire? No volume button ranks first in dislikes, while the lack of camera is second, and battery life third (see chart).

ChangeWave also asked shoppers where they'll be spending their money online over the next 90 days and found that Amazon continues to outperform all of the other major online retailers included in the survey combined (see chart at bottom).

"One-in-five respondents (20 percent) say they'll spend more money online at Amazon.com vs. 11 percent less--numbers that overwhelmingly dwarf the other online retailers surveyed," Changewave said.

Changewave Research

Changewave Research

Changewave Research