Upwork Inc. (UPWK) is starting to look more than just a place for quick freelance gigs. With its new Business Plus plan, the company is going after bigger clients—and it’s working. In the last reported quarter, the number of active clients on Business Plus more than doubled. About 40% of them are brand new to Upwork, which is impressive considering Upwork hasn’t even spent much on marketing the plan. That shows the offer is meeting a clear need.Business Plus gives clients a smoother hiring experience. They ...