I've just spent the last few hours researching the latest "forum spam" news.
Some of the websites visited were the big SEO (Search Engine Optimisation) sites in which discussions were being held as to the best types of marketing. Of course there were plenty of articles about how to market to forums like ours. Actually, I was surprised at how one of the larger professional marketing forums dissuaded forum spamming and encouraged their members to abide by forum rules and add value to the forums. Part of the reason is that they are more interested in building up a person's name as an "authority" rather than selling things. You'll see this in magazine article-style posts that have a specific name tied to it.
I also checked out the website administration forums. Many sites and forums have experienced dramatic increases in increasingly human-like bots and real humans from Indian and Chinese "spam shops" joining forums. It's partly due to the large Russian botnets being dismantled late last year and their owners trying more lucrative spamming techniques.
The latest forum bots go some way to explain the behaviour of spammy messages. One Russian product in particular, which sells for a LOT of money, can get past most forum protection and simulates people by analysing existing forum messages in the target then searching for similar posts in other non-related forums and copying those into the target along with a payload of spam. It runs automatically, after a few hours of "training" by an experienced human operator.
It also has a delayed payload - adding members to a forum but not posting until months later. Or adding members, adding a dozen or so simple one or two-line posts, then returning months later and EDITING the messages to include spam links. This is all automatic. One important warning for any forum can be inferred from this - never allow members to edit their own posts, or only allow a very small window of time after the initial submission for an edit.
The product boasts a database of common sentences that can be dynamically adapted with the forum subject keywords. For example, "thanks for your interesting post about diets. It is very helpful. I will try it soon." The keyword "diets" is the forum subject keyword that is inserted into the text.
Most human forum spammers are recruited from India (due to the prevalence of English-language skill) for around $1 to $3 per day. Other forum spammer sweat-shops are located in places such as China and The Phillipines.
You can read a discussion about an advertisement for professional forum posters here:http://metalmonstermarketing.com/blog/l ... organized/
Another subtle spam technique is Member-list spam. Automated software, such as the Russian one I mentioned earlier, can be programmed to add members with email and website links to lists and do nothing else with them. Search engines such as Google, Bing and yahoo crawl and find these and increase the link count and ranking of these websites, mostly drug and porn.
Since the major web search engines seem to be registered users of this forum and can access the memberlist, and of the 9700 registered users perhaps 9000 are member-list spam items, it appears the site might contribute to the search engine rankings of the spammer sites unless the pages' o-follow directives are honoured by the search engines. In light of this I think it's probably time for removal of zero-post members.
It's not all doom and gloom, however. There are some excellent articles out there on how to minimise the damage of this relatively new breed of spammers, plus excellent anti-forum spam sites like "Stop Forum Spam":http://www.stopforumspam.com/
Hopefully someone will find my notes on this fascinating problem of some interest.