Spam is subtly shifting from nuisance to illegality, says a new report from security firm Clearswift.
What type of spam is cluttering your inbox?
It has been measuring spam for the past year and has noticed a change in what is cluttering people's inboxes.
It seems spam is a hotbed of financial scams as well as a black market for fake pharmaceuticals and software.
"Spam is now being used as a channel for a plethora of malicious and illegal activity," said Clearswift's technical director, Alyn Hockey.
In the early days, spam was dominated by pornography but these days an opened junk e-mail is far more likely to be offering a miracle diet than an invitation to view porn.
"Porn has reduced due to the fact that the filtering technology has improved so there is less getting through," said Mr Hockey.
The fact that more people have got broadband connections could also play a part in the decline as people find other ways of viewing pornography.
While porn is languishing at just 4.8% of spam, compared to 21.8% at the same time last year, financial and pharmaceutical spam now makes up nearly 70% of spam.
WHAT IS SPAM MADE OF?
1 - Finance (39%)
2 - Healthcare (30.6%)
3 - Other (15%)
4 - Direct Products (9.6%)
5 - Porn/Profanity (4.8%)
6 - Scams (1%)
"Buying Viagra over the net, even if it costs $100 for a course, is less embarrassing for people and they may be prepared to pay for the anonymity of it," said Mr Hockey.
Mr Hockey estimates that spammers have around a one in 40,000 hit rate with products they are selling online.
And spammers are keen to keep up with the latest offline trends.
"When Arnold Schwarzenegger was campaigning to be governor of California, there was lots of spam about offering Schwarzenegger memorabilia," said Mr Hockey.
In the run-up to Christmas direct products such as toys and games dominate inboxes.
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After the Christmas binge, spam is more likely to be about miracle diets that can banish the excesses of the festive season.
"Spammers do take notice of what is going on in the world," said Mr Hockey.
Similarly spam has reflected the growth of criminal activity online.
For criminals, spam provides the perfect cover to direct people to disreputable websites without being traced.
Known as web-phishing, spam directing people to seemingly legitimate sites in order to steal credit card details and other personal information is on the rise.
Both hackers and spammers need networks to distribute their wares and Mr Hockey believes they are increasingly working together to make use of zombie PCs.
Zombie PCs are home computers infected by a trojan horse which effectively opens a backdoor for hackers and spammers to use them as a platform for sending viruses and spam.
"These two camps are likely to be helping to perpetuate the other," said Mr Hockey.
Scams such as web-phishing are likely to get worse before they get better but Mr Hockey predicts that eventually, like pornography, it will decline.
"Pornography was offensive so there was a real push to try and stop it and the same will become true of phishing once people become aware of it," he said.