Pornographic spam is on the decline and is being replaced by growth in areas such as healthcare and online gaming, according to mail-filtering firm Clearswift.
The change reflects an evolution in the kinds of spam that users are receiving, as filtering forces spammers onto pastures new, and success for certain products motivates the spammers to focus on areas where there are rich pickings.
The statistics, based on spam emails received by Clearswift's 16 million users, show changing trends in the type of spam being sent. Pornography made up just 15.2 per cent of all spam -- down from a high of around 20 per cent -- while online gaming -- such as casinos -- is now the source of 7.2 per cent of spam, a figure that is rising rapidly due to a loosening of gaming regulations.
However, the rise of healthcare products continues unabated despite the fact that they have long been recognised as the source of much of our spam. Viagra, diet pills and 'body enhancements' are all common offers from the healthcare black market, but there appears to be little we can do about it.
While subject lines may claim "I grew my length three inches," the more incredible increase is the one which has seen healthcare related spam rise from 18 per cent of the total to 26 per cent in just one month.
Clearswift attributes the growth -- which is a sure sign of success for the spammers - to the fact that the anonymity it affords appeals to consumers. Impotent men who buy the wonder-drug Viagra would apparently rather take a chance buying it from a company that has spammed them rather than walk into the family GP's office and get it on prescription.
Alyn Hockey, director of research at Clearswift, said anonymity and convenience are definitely factors in the growing success of healthcare online but said seasonal variation may also play a part in the changing profile of spam.
"In any one month you may see a number of different campaigns from spammers. Maybe this isn't a good time for porn or maybe it's just a good time for Viagra -- the sun's out and people are feeling good and looking for something to pep them up a bit," he said.
However, he added that it is likely the success that spammers are finding with healthcare will see other forms of spam fade away.
"Spammers can probably see better returns from selling drugs," added Hockey.