North Jersey – Betfair officials have taken a look at who in New Jersey is using their online gaming platform since the entertainment option was legalized in late November. Newark and Jersey City are among the top half-dozen municipalities participating in the gambling – no surprise given that they also rank 1-2 in population at about a quarter million residents apiece. Toms River, which ranks 8th in the state according to the 2010 U.S. census, also is on the list. The others are Old Bridge in Middlesex County (18th, not sure how they wound up here), Hoboken (34th, with a…