Apple has sold more than 2 million iPads, but there may be an opening for rivals should they get their device act together, according to a Retrevo study.

Retrevo polled more than 1,000 people about the iPad ahead of Apple's WWDC powwow. In short, the findings go something like this:

52 percent of those surveyed said they don't need an iPad;

38 percent of folks say the iPad is too expensive;

10 percent are looking for a good excuse to buy one.

Then Retrevo asked about Android tablets.

53 percent say they'd get an Android-based tablet if it were cheaper than an iPad;

33 percent would get and Android tablet if Verizon were the carrier;

28 percent say they'd get an Android tablet if it were discounted as part of a subscription service.

This study gets to that iPad first mover thing I've been harping on. Apple is strong out of the gate with the iPad, but it's unclear how long it will take Android-based tablets to catch up on functionality. Thus far, I haven't seen any so-called iPad killer that could really give Apple a run.

The longer it takes for a credible competitor to emerge, the more runway Apple has. Apple may not get an iPhone-ish lead on rivals, but the Android army can't take its time either.

Judging from Retrevo's results, price will be a differentiator. However, Apple never competes on price---although pricing is going to be competitive---so a bunch of cheap tablets aren’t going to derail the iPad. Things will get interesting if a Droid tablet subsidized by Verizon Wireless hits the market though.

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