Pills, porn and poker, the so-called 3 Ps, are the most common forms of business which use E-mail spam and other forms of spamvertising. In many cases, these sites are of dubious legality and are often fronts for fraud.
The "pills" sold are usually treatments of impotence, such as real or purported Viagra or Cialis tablets, to be delivered without prescription, although other prescription medicines are also advertised. Some pill advertisements suggest that they can offer penis enlargement. If the pills are actually delivered, they are typically counterfeit drugs.
Pornography websites are also heavily advertised in this way, as are (as of 2005) online poker websites. Online Poker ads have since been reduced since the 2006 legislation that puts restrictions on online gambling in the United States.
All of these businesses transact their business through the use of credit cards; in many cases, the spamvertised sites are simply vehicles for credit card fraud.
Recently, fake goods such as fake Rolex watches have appeared as another common category of spamvertised goods, along with OEM software, and stock spam e-mails promoting a particular stock.
AOL documented an "unscientific" list of the subjects of the spam most widely sent to its members during 2003. In alphabetical order: