The "nofollow attribute" effectively instructs search engine crawlers not to follow a particular link to its specified destination, through the insertion of a code to that effect.

The "nofollow attribute" was a creation of Google sometime about 2005, ostensibly to counter spamming. To what extent this objective has been achieved is debatable.

The "nofollow attribute" has the following consequences for the web page at the specified destination.

Ideally,

1. It's contents will not be crawled through this link.

2. No link juice(pagerank) will be passed from the source web page.

3. The specified web page will not be indexed through a direct result of its link on the source web page.

4. The anchor text used on such link will not be deemed reflective of the keyword phrase the destination website is relevant for.

Hitherto, a predominant number of sites/blogs had nofollow comments retained. Partly due to ignorance, some maintained it, while others did, purely of their own volition.

It is pertinent to state that most blogs are nofollow enabled by default.

How do you verify the sites that have "nofollow" enabled?

Simple!

Two major ways:

1. Visual inspection of source codes

As you may know, each web page is made up/structured by html source codes which can be viewed by right clicking your mouse and visually inspecting to determine which sites or links have the codes indicated above inserted somewhere within the web page.

2. Installation of SEO for Firefox add on.

This is one of the many reasons why you should be using the Firefox browser as the installation of this add on enables you to view quite easily, whichever link has this "nofollow attribute" enabled. A colour, usually pinkish/redish covers these "nofollow" links while the links that are "dofollow" are left plain.

Should those just starting a home based internet business have this "nofollow attribute" maintained?

I will say no for the following reasons.

1. The "nofollow attribute" stiffles audience participation in blogging with its attendant disadvantages.

(a) One such disadvantage is that traffic is significantly curtailed. This no doubt is very crucial to a beginner internet marketer who at that stage may not be able to significantly enhance visitor traffic to his blog through other internet marketing methods.

This has a bearing on the Alexa rankings of the webmaster's site and as is well acknowledged, this is a key statistic for judging site performance.

(b) Another of such disadvantages is that it discourages content creation by the visitors to the site via their comments as they will not be encouraged to comment if they see no gain in it for them by way of "dofollow" backlinks.

This also reflects negatively on another vital site performance statistic (pagerank), as enhanced content is a contributory factor which can improve pagerank

2. The main reason - spamming (from Google's perspective) which necessitated this attribute can now significantly be curtailed by the introduction of many wordpress plugins such as akismet, captcha etc.

Does this attribute have any advantages whatsoever?

Certainly yes, in the following circumstances.

1. It can be used in isolated cases where you insert outbound links to sites you cannot vouch for so that your site does not get punished by the search engines if it is discovered that such sites are "bad neighbourhoods" or "scam sites" or "link farms".

2. Can be used entirely, in the very unusual case where spamming becomes such a worry even to a newbie internet marketer and cannot be combated by various measures already highlighted above.

3. Can be used entirely, where the webmaster has become so established that interaction with his subscribers/audience is not so important vis-a-vis effect of spamming on his site or he is not significantly dependent on this mode (blog comments) in interacting with his subscribers/visitors such that it does not materially affect his business if he turns on this "nofollow attribute".

In conclusion, in starting your own small business, you need to enable nofollow attribute at the least, for comment