Web spam is more viral than email spam.
In email spam they target only known email id, which they get from various sources like small consultancies or from training institutes or by doing some social engineering ;). Mail providers like Gmail, Yahoo are too intelligent to send it to spam folder without giving you trouble. So, you are somehow safe in case of email spam.
But in case of web spam, they want us to browse their website to buy or advertise their products. Web Spammers main motto is only to earn money. We need to be sure before any comment or post is getting published in our website. In worst case you may lose permanent genuine readers too!, which will ultimately affect your site and your revenue if any.
Web spammers are techie and hire social engineers too
Web spammers are not always automated bots or scripts. Now a days even employees from that target brand do web spamming. They are very good a SEO and know what to write to pass various anti-spamming modules. They will write like authentic commenters and will insert one link somewhere or will post the link as their homepage.
I have seen many such cases in WordPress and Drupal. After seeing the comment manually, sometimes you would get confused that “are they real reader who are writing such a good and almost real comments!” You would approve the comments most of the time, if you are not so much techie and well aware of such tricky spams. Specially, non-tech bloggers become victims of it.
So, make every comment under moderation or use some useful anti-spam plugin like Akismet (For WordPress users) and review it manually. Check every url and text. If you find anything irrelevant to your post or site, simply ignore it. Don’t show any temptation to show-off thousands of spammy comments in your site, rather have very few but original and worthy comments only. Like my site is for technical purpose then why to entertain shoes, apartment, bikes advertisements even though they seem real?
Stop Web spammers from advertising through your site/blog
You may not feel or experience that your site is being spammed (advertised in other terms) without your permission to other people/companies (through spammers). How do they do it? It’s very simple! They will approach you for guest blogging related to your site’s niche and will insert one or two external links, which is nothing but the advertisements through your site. Whatever money they will earn by selling those links, they will keep 100% of it and you will get nothing in return. In return, it may hamper your PR, Alexa Rank and genuine users too! So, think before you allow such spammers
Verify first even if they ask for just backlinks.
As I said, if someone approaches you 2 way backlinks, to boost mutual traffic and involve each other’s sites, then also verify first. I t should not harm your site, your readers and your PR.
But, if it is simply a kind of guest post with one or two links either in the content or at Author Bio section at the bottom. Be very careful before approving such links. You should allow only when it is of same niche as yours, should not be any malware or any non-related links. This trick is being used to redirect traffic from your website to their sites through those links.
IMHO, you should approve such posts very carefully and put it under paid post and charge them. Once, you will charge minimal amount, they would think before posting, because they are now barred from free advertisement.
Spammers are human being and employ human being.
When we hear the word like spams, malware etc we think they are just automated scripts/programs. But, its not always true in case of web spammers. They are human being and employers hire very skilled technical/content writer to write very specific suited for your website. But ultimately, it is nothing but the spam.
Usually those paid employess are low paid or unemployed students, professionals (who are having low educational background) or SEO people. Companies hire them for temporary purpose to advertise its own company’s new product or newly launched website. This way they can be viral and capture the market easily. Try to avoid being exploited by such web spammers.
I am not allowing any guest post now and if they approach, I would follow all above said steps and would charge and will stick to my and my site’s ethics to make it unharmed and popular for my trusted readers.