E-mail spam, also known as unsolicited bulk email (UBE) or unsolicited commercial email (UCE), is the practice of sending unwanted e-mail messages, frequently with commercial content, in large quantities to an indiscriminate set of recipients.Spamming is the abuse of electronic messaging systems to indiscriminately send unsolicited bulk messages.
General costs of spam
In all cases listed above, including both commercial and non-commercial, "spam happens" because of a positive Cost-benefit analysis result. Cost is the combination of
- Overhead: The costs and overhead of electronic spamming include bandwidth, developing or acquiring an email/wiki/blog spam tool, taking over or acquiring a host/zombie, etc.
- Transaction cost: The incremental cost of contacting each additional recipient once a method of spamming is constructed, multiplied by the number of recipients.
- Risks: Chance and severity of legal and/or public reactions, including damages and punitive damages.
- Damage: Impact on the community and/or communication channels being spammed.
Benefit is the total expected profit from spam, which may include any combination of the commercial and non-commercial reasons listed above. It is normally linear, based on the incremental benefit of reaching each additional spam recipient, combined with the conversion rate. Spam are categorized instant messaging spam, Usenet newsgroup spam, Web search engine spam, spam in blogs, wiki spam, mobile phone messaging spam, Internet forum spam and junk fax transmissions.