Groupon Inc. shares fell ater a survey from Susquehanna Financial Group indicated that about half of merchants that have offered a daily deal have no plans to do so again in the next six months. The shares were trading below their initial public offering price of $20 in November. The company is the biggest seller of daily deals, which provide discounts of as much as 90 percent at restaurants, nail salons and other businesses. Susquehanna and daily-deal aggregator Yipit surveyed almost 400 merchants to determine the value of the services and the concerns companies have about using them. While 80 percent of respondents were satisfied with daily-deal companies, about 52 percent of merchants said they’re not planning to use deals in the next six months.