Christmas is coming, and so is the mad rush by retailers to hire seasonal workers. An estimated 704,000 jobs are up for grabs this holiday season, according to outplacement firm Challenger, Gray & Christmas. The figure marks a significant increase from years past and reflects strong consumer confidence as the economy rides high. Unemployment reached a 48-year low in September, and Americans have more disposable income to spend on gifts, food, furnishings and other goods that typically help retailers get their books in the black by the New Year. The bounty of jobs means more competition to hire the best workers, and some retailers are sweetening the pot with flexible schedules, bonuses, gift cards and other perks to lure enough staff to get through the holiday rush. Others, like Amazon, are supplementing their workforce with robots and focusing on logistics. The retail giant announced it would hire fewer workers than in the last six years and is looking primarily for drivers to deliver packages.…