NEW YORK (CNN/Money) - Internet-addicted job seekers may be blamed for the prolonged duration of unemployment, according to a report issued Tuesday by recruitment firm Challenger Gray & Christmas Inc.

Since the onset of the recession in March 2001, the average duration of unemployment has grown to 15.2 weeks, 23 percent longer than the 12.4 weeks it took job seekers to become re-employed during the pre-Internet-era recession that lasted from July 1990 to March 1991, the report said.

"A growing number of unemployed Americans waste time browsing the estimated 4,000 to 5,000 online job sites, blanketing them with resumes, and then waiting for callbacks. It is a formula for long-drawn-out joblessness," said John Challenger, CEO of the recruitment firm.

While the Internet has the potential to be very useful for job seekers, Challenger said it has become the primary tool for many, when it should be considered secondary to the traditional technique of meeting prospective employers in person.

In addition to prolonging job search efforts, the Internet is slowing the hiring process for the employer too, according to the study.

The survey said 92 percent of recruiters and hiring managers were inundated with irrelevant responses, and 71 percent said a majority of the resumes they received in response to an online job posting did not match the job description.

Challenger Gray & Christmas, however, said the Internet has definitely revolutionized job searching, but job seekers should learn how to use the Internet as a tool, instead of relying on it completely.