Year-to-year, the number of online banking customers grew to nearly 40 million during the quarter, a 27 percent increase over the same period a year ago, ComScore Networks said. Usage of online bill payment services grew 36 percent during the same period.
Nevertheless, the quarter-to-quarter number indicated a slowdown.
"It is clear that adoption rates are slowing," Serge Matta, a director at ComScore, said in a statement.
Bank of America led the industry in bank bill payments. Its 5.1 million active customers accounted for more than half of the industry's total number of bills paid online through banks in the fourth quarter. Citibank, however, has the highest percentage of customers who bank online at 37 percent, followed by Bank of America, 34 percent.
Incentives and easing security concerns were the primary drivers behind customers adopting online banking. Fully 33 percent of online customers surveyed by ComScore said free banking products were an inducement, and 23 percent said they felt more secure about online banking than they did before.
Washington Mutual's free-checking campaign helped attract the most new enrollees in the quarter. The bank signed up 43 percent more customers than in the same quarter a year ago.