For example, the standard-advice group was told how much money the typical smoker spends on the habit. People in the tailored group were told how much they themselves likely spent each week.

After six months, nine percent of smokers in each group said they had been smoke-free for the past three months.

The findings are somewhat surprising, according to lead researcher Dr. Dan Mason, of Cambridge University.

On the other hand, he said in an email, the general-advice group got much the same information as the tailored-advice group -- albeit in a "more generic" way.

Smokers who got tailored advice were also invited to return to the website four weeks later to get a progress report. The problem, Mason's team found, was that few of them did -- less than one-quarter of the group.

Because the nine percent of each group who succeeded in remaining abstinent for three months were not compared to a group of smokers receiving no advice, "It's a pretty tough test," Mason said, "as we are really only testing the tailoring and not so much the content of the advice."