When to Use a No Follow Tag
Using no follow tags on your website should always be done with caution because a no follow can often times provoke further investigation from the search engines. Keeping that in mind, you better make sure everything else on your website is 100% squeaky clean. If you are not sure how to manipulate PageRank throughout your website by the clever use of no follow tags don’t worry about it but there are some important instances you should use a no follow to either be safe or simply not waste your link power in areas it where it is clearly not needed.
If you have a paid advertising model on your website where you sell ad space those ads should always have a no follow tag on them. Since Google has come out and said paid links are bad and very frowned upon you want to make sure you don’t run the risk of receiving a penalty by selling links, because a paid advertising spot with a do follow tag on it is nothing more than a paid link in the eyes of the search engines.
It is very popular for website to have a series of trust badges from the Better Business Bureau and sites like VeriSign that sometimes link out to those sites. You don’t need to pass on any link juice to those sites if you don’t have to, so put a no follow tag on that link to let the search engines know nothing is passing on to those websites.
Internal linking to pages sometimes doesn’t need to be a followed link. For example, if you are linking to a contact page or maybe a testimonial page that might not need to have link power passed over to it, however, if you are linking to an important service or product page than you will want to leave the do follow status on it.
Sculpting the flow of your PageRank needs to be done very carefully and within guidelines at all times. Once the search engines catch you doing this they will monitor you like a hawk and give more weight to analyzing your moves so make sure it is important and everything else you do is by the books.