Self Promoting Advertising Material, Spam...
I have retired from running online businesses and moderating on a large business foum, but my experience of spam is this..
As a wholesale business owner on the web I received hundreds of email offers of cheap SEO for better Google search results.
OK, so what has that to do with spam?
As a forum moderator spam posts were the result of those cheap SEO invites.
How? Well they joined forums using bots and made the same introductory post on hundreds of forums or added a post to an established thread and in it they would covertly put a business web address and/or keywords.
Or they would make a comment and add a web address in smaller or even an invisible font at the end, there was one on this forum today. You just highlight the thread text to reveal what was invisible.
There is invisible text here....>>>>> Euromodeller
Because forum software is third party it can be difficult and/or expensive to customise to stop spamming so a business decision is made, the return on investment is poor so it gets veto'd.
There are apps (programs back in my day) that could alert you to spammers, but that is only effective if every forum has the software and each spamming member's email address is shared with the app.
So, as a forum owner, it is a very difficult decision to make, use profits up on software or use profits to regenerate business?
They are one step ahead of each rendition of captcha.
As members we should not reply to spam threads, they are monitored for results, but shold use the warning triangle below the post to report it to the mods.
edited to add, eBay is suffering huge attacks of false bidders each day, these bids are made by new members within seconds of the auctions ending, they win the auction and don't pay, it's not spam but is auction wrecking.
eBay are having difficulty stopping the bots from joining as new members. So even a multi million dollar corp. has trouble with new memberships causing problems.