Chart of the day: iPad Web presence is up, Kindle downApril 18, 2013: 2:57 PM ET
The iPad's usage share in North America rose in March for the first time since December.
FORTUNE -- Despite increased competition from tablets running Google (GOOG) Android, the presence of Apple's (AAPL) iPad in the Chitika online ad network rose in March to 81.9%, up from 80.5% in February.
According to the report Chitika issued Thursday, the rest of the tablets are all distant also-rans.
In the same one-month time period, it saw the presence of Amazon's (AMZN) Kindles fall to 7.5% from 8.0% and Samsung's Galaxy Tab rise to 4.3% from 4.2%.
Chitika, which says it got its March data by sampling tens of millions of ad impressions in the U.S. and Canada between March 15 and 21, attributes the iPad's improved share in part to the discounts Apple began offering on refurbished iPads in mid-March.