Bayesian filtering works very well, measured at greater than 99.9 percent accuracy at detecting spam and other unwanted e-mails. In his paper, "A Plan For Spam", Paul Graham popularized Bayesian filtering on word groupings to prevent spammers from getting their messages across. After all, how can you sell a new genital enlargement cream without using the words "enlargement" or "bigger" in conjunction with certain other words? Eventually, spammers are reduced to incoherence through vocabulary starvation.
What if I do want discount prescription offers? Bayesian filters will "learn" that, too. Statistical filtering can be very specific to a given user's requirements.
