Apple's iPad Air reveal has easily been the business tech story of the day, and competitors were more than ready to attempt to brand-jack the news. Samsung, Microsoft, Nokia, LG Mobile and Motorola are examples of head-to-head tablet rivals that bid on iPad-based keywords in what appeared to be an unusually busy Twitter ads marketplace.

Brand-jacking via Twitter around news events is still a fairly new marketing practice and therefore largely unproven. Presidential candidates one year ago were notably testing out the idea during the parties' national conventions as well as during their debates.

Look for more Promoted Tweets to target competitors' misfortunes rather than highlights such as the iPad announcement today. For instance, a source close to the situation recently told Adweek that Walmart last holiday season aggressively and successfully purchased Twitter ads around Best Buy's shipping and product-availability ills.

At any rate, here is a sample of the brand-jacking that came to light around Apple's event today.