Spam increases labor cost for companies since employees have to sift through and delete the tons of spam before they can distinguish purchase orders, support questions and other client information.  Many product orders have also been deleted by mistake due to enormous amounts of spam in a company inbox costing the company thousands of dollars.

Spam is harassing, especially when you have ASK spammers not to continue sending spam to your mailbox.  99% of the time, this only adds spam to your mailbox since spammers network together and exchange your email address to each other for profit.  Spammers have NO respect for you or your company and if they can make an extra buck selling your email address, they WILL and do on a regular basis.
 

Spam costs ISPs (Internet Service Providers) more money since bandwidth cost is increased each time a spammer sends thousands of email spam each hour.  This then increases YOUR cost since the ISPs have to charge you more per month since THEIR cost is more.
 

Spam slows down server connections worldwide when they are being broadcast since they use up so much bandwidth, YOUR bandwidth you may be using to access a website.  If you are on a dial-up modem, you may also experience disconnections repeatedly due to spammers sending their smut, scams and junk through cyberspace.
 

Although there are laws in several states to prohibit spam, very little is being done by the government to help you get rid of your annoying spam.  There are laws to prohibit unauthorized faxes from being sent to your fax machine and laws to prohibit pornography from being sent by the U.S. Mail service, but NOTHING to prosecute spammers from sending 9-year old children porn or sending embarrassing or simply annoying ads to secretaries and other employees at company email addresses.
 

Software filter programs are sometimes helpful, but are not 100% effective in getting rid of ALL spam and only letting in friends, family, business clients, etc.
 

Keyword filters on many email programs are not 100% effective since spammers use tricky ways of wording on subject lines and in the body content of the email itself to fool the system into letting them in.
 

Web Sites - CDT received the most e-mails when an address was placed visibly on a public Web site. Spammers use software harvesting programs such as robots or spiders to record e-mail addresses listed on Web sites, including both personal Web pages and institutional (corporate or non-profit) Web pages.
 

Junk e-mail, a.k.a. spam, inconveniences tens of millions of Internet users and imposes huge costs on ISPs. Armed with lists of e-mail addresses, "spammers" send billions of e-mail messages every day -- messages that most users don't want.
 

It is often difficult or impossible to tell how a spammer acquired a user's e-mail address. Was it a result of some activity the user engaged in? Did the user give his/her e-mail address to the wrong person? Was the user randomly targeted? Are there steps the user could take to avoid such spam in the future?