The growth of New Jersey’s Internet gambling market slowed somewhat in its third full month of operation, with the Atlantic City gambling websites posting a nearly 9 percent revenue increase in February. The 16 online gambling sites had posted a 28 percent gain in January, to $9.5 million. In February, the online sites won $10.3 million. The numbers released Wednesday by the state Division of Gaming Enforcement show the market starting to plateau. But Brian Mattingly, CEO of 888 Holdings, which partners with Caesars Entertainment to offer online gambling in New Jersey, is pleased with the fledgling market thus far....