different media:
E-mail : An industry of e-mail address harvesting is dedicated to collecting email addresses and selling compiled databases. Some of these address harvesting approaches rely on users not reading the fine print of agreements, resulting in them agreeing to send messages indiscriminately to their contacts. This is a common approach in social networking spam such as that generated by the social networking site Quechup.
Instant Messaging: As instant messaging tends to not be blocked by firewalls, it is an especially useful channel for spammers. This is very common on many instant messaging system such as Skype.
Newsgroup and forum: Newsgroup spam is a type of spam where the targets are Usenet newsgroups.
Mobile phone: Mobile phone spam is directed at the text messaging service of a mobile phone. This can be especially irritating to customers not only for the inconvenience but also because of the fee they may be charged per text message received in some markets. The term "SpaSMS" was coined at the adnews website Adland in 2000 to describe spam SMS
Online game: send spam via the in-game private messaging system, via using emotes to gain attention, and by yelling publicly to everyone in the area.
Spam targeting search engines: view "http://en.wikipedia.org/wiki/Spamdexing"
Blog, wiki, and guestbook:this type of spam took advantage of the open nature of comments in the blogging software Movable Type by repeatedly placing comments to various blog posts that provided nothing more than a link to the spammer's commercial web site.[6] Similar attacks are often performed against wikis and guestbooks, both of which accept user contributions.
Spam targeting video sharing sites: Video sharing sites, such as YouTube, are now being frequently targeted by spammers. The most common technique involves people (or spambots) posting links to sites, most likely pornographic or dealing with online dating, on the comments section of random videos or people's profiles. Another frequently used technique is using bots to post messages on random users' profiles to a spam account's channel page, along with enticing text and images, usually of a sexually suggestive nature. These pages may include their own or other users' videos, again often suggestive. The main purpose of these accounts is to draw people to their link in the home page section of their profile. YouTube has blocked the posting of such links. In addition, YouTube has implemented a CAPTCHA system that makes rapid posting of repeated comments much more difficult than before, because of abuse in the past by mass-spammers who would flood people's profiles with thousands of repetitive comments.
Yet another kind is actual video spam, giving the uploaded movie a name and description with a popular figure or event which is likely to draw attention, or within the video has a certain image timed to come up as the video's thumbnail image to mislead the viewer. The actual content of the video ends up being totally unrelated, a Rickroll, sometimes offensive, or just features on-screen text of a link to the site being promoted.[7] Others may upload videos presented in an infomercial-like format selling their product which feature actors and paid testimonials, though the promoted product or service is of dubious quality and would likely not pass the scrutiny of a standards and practices department at a television station or cable network
SPIT: spam, usually using SIP (Session Initiation Protocol).