How much of a stranglehold does Apple have on the tablet market? Well, according to new data from the Chitika Ad network, the iPad accounted for 91% of the hundreds of millions of Web traffic impressions sampled during the week of June 4 -10. Not bad, but that actually represented a decline of 3.5% from 94.6% in May, Chitika found. “Coming in at a very distant second place was Samsung's Galaxy Tab, which captured only 1.7 percent of tablet Web traffic, followed by Acer Iconia, Toshiba Thrive, and Asus Transformer Pad,” CNet notes. There appears to be a new leader in the e-reader battle between Barnes & Noble's Nook and Amazon's Kindle Fire. Indeed, the Nook has overtaken the Kindle Fire in Web traffic impressions. Compared with an earlier study of tablet traffic, the Kindle Fire maintained its 0.71 percent market share, while the Nook surged past the Kindle Fire with a 0.85 percent market share. "In the time since that study, Barnes & Noble has launched a new advertising campaign, and their newest device sold out within weeks," Chitika pointed out. "While that device is a simple e-reader without Web browsing capabilities, the increase in Nook use may be attributed to brand familiarity through these advertisements."