Dive Brief: 

• Apple's competition sought to "brand-jack" the tech giant's iPad Air announcement with Promoted Tweets containing iPad-related words for Promoted Tweets. 
• Samsung, Microsoft, Nokia, LG Mobile and Motorola were all involved in the brand-jacking. 
• The practice of brand-jacking is new enough that its effectiveness has yet to be measured. Presidential candidates in last year's election were the most notable early adopters of the practice. 

Dive Insight: 

The iPad brand-jacking is relatively mild, but the practice is one that has potential to get ugly—especially if it's found to be effective. The directly competitive method of brand-jacking on Twitter should be used with caution.