Businesses may have difficulty getting much done today, as workers return from Thanksgiving weekend. That's because many of their employees will be shopping online.A study conducted by polling firm Omnibus, on behalf of digital coupon site RetailMeNot.com, found nearly 90% of working Americans plan to shop or browse online for gifts during work hours on Cyber Monday. More than 20% plan to spend four hours or more doing so.Trae Bodge is senior editor for RetailMeNot. She says consumers might be better served by postponing some of their online shopping in order to get better deals."Cyber Monday is reliably for electronics and entertainment items and clothing and accessories. Those are the categories where you will find the deeper discounts. So focus on those items in those categories and look for great deals within those categories and take advantage of those deals that day, and then as we get a little closer to Christmas, do your other purchasing along the way."The survey found online shoppers plan to spend an average of a $167 per person on their gift list.Nearly 90% of employees to shop online during work hours on Cyber Monday