Advertising is the next revenue driver for technology giant Apple and the company is already making strides toward building it, according to Needham’s Laura Martin. “We believe advertising could be a meaningful upside driver for AAPL’s Services revenues and gross profit, especially based on AMZN’s success in growing its advertising business to $37B in 2022E, up from $4B five years ago,” wrote Martin in a note to clients Wednesday. “We note…