The message isn’t new. Amazon (NSDQ: AMZN) has been pointing out for months that the Kindle E-ink screens are easier to read in the sun than LCD screens. The distinction became even clearer with its new Kindle 3, boasting 50 percent better contrast and a screen that can be read “with no glare, even in bright sunlight.” But Amazon wasn’t naming names — until today when it slipped a new ad into the rotation. No more quirky cuteness with fey music or a couple sedately sitting on the beach reading their Kindles. This one is as direct as the Corona ad where she squirts lime juice at his wandering eye. Watch as sassy Kindle (the WiFi-only $139 edition, of course) takes on hapless iPad.