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You aren’t providing free links to spammers.

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Spammers are less motivated to spend time on your site.

Avoiding Comment Attacks Using Nofollow

Many black hat spammers will use the comment section of a blog or guestbook, or forums, to post spam

messages and links that promote their web sites.

Adding the

rel

=”

nofollow”

attribute to a link will inform the search engine that that particular link is

not audited by your site, and should therefore not count as a trusted vote for the popularity of the linked

site. And though this strictly doesn’t prevent spam, it does remove a lot of the motivation that results in

a spammer targeting your site. The link will still work, but it will no longer be as desirable to a spammer

because it offers a diminished link equity value.

In reality,

nofollow

has far from eliminated comment and guestbook spamming. Unfortunately, it

does not eliminate the need for manual auditing and spam filtering. It is just a deterrent.

You can use the same technique when including links to sites that you don’t want to “vote.” Here’s an

example:

<a rel=”nofollow” href=”http://too.much.spam”>Bad site!</a>

It is also important to realize that too many links without

rel=”nofollow”

may hurt your rankings if

they are linking to “bad neighborhoods” as well as damage your reputation and credibility. All major

search engines currently support this the

nofollow

feature.

Automated scripts may still target your site, only because, frequently, the spamming is done in bulk,

and the spammer has not investigated your site specifically. In practice, however, using

nofollow

is

likely to cut down on spam. Either way, if

nofollow

is employed, the damage is mitigated as it can

only damage visitor perception, not search engine rankings, because the links will not be seen as votes

to a bad neighborhood by a search engine. Collectively, because most web sites will begin using this

feature, it will yield inferior results, and spammers will use such techniques less frequently.

In the exercise that follows you create a little PHP “nofollow library,” which employs a regular expres-

sion that alters all links in a text buffer by adding the

rel=”nofollow”

attribute, but only to links that

are not in a predefined “white list.”

Creating and Using a Nofollow Library

1.

If you haven’t already done so by following the previous chapters, create a folder named

include

in your

seophp

folder. Then create a file named

nofollow.inc.php

in your

seophp/include

folder, and add this code to it:

<?php

// include config file

require_once ‘config.inc.php’;

// finds all the links in $str and processes them using fixLink()

function noFollowLinks($str)

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Chapter 8: Black Hat SEO

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