Despite the promise of more money flowing in, investors can't take their minds off eBay's ( EBAY) other worries for long.Indeed, the enthusiasm triggered by eBay's fee increases seemed to dampen just one day after the auction giant announced them. Shares of eBay closed Friday off 81 cents, or 2.6%, to $30.78. The pullback followed a gain of about 4% on Thursday, when the company said that it would introduce a slew of new fee increases for its auction services. Kicking off the new year with fee increases has become routine for eBay. "An important part of any business strategy is a regular evaluation of our pricing structure," eBay North America President Bill Cobb wrote on the company's blog. Usually, "we make changes on an annual basis at the beginning of the year," he wrote. Some analysts saw the latest round of fee hikes as a bullish sign that eBay didn't need drastic measures to take further advantage of its slowing core auction business. The fee increase is "consistent with our view that eBay continues to have some (modest) pricing power and is the preferred action versus more bearish case of eBay needing to lower fees to maintain listings growth," wrote Merrill Lynch analyst Justin Post in a research note on Friday. Post also wrote that sellers will pass on a portion of the higher fees they are paying by charging buyers slightly more. Merrill Lynch makes a market in eBay shares.