Since learning about DoFollow and NoFollow rules, I’m becoming more and more cautious to provide any links outside from my blog. Any links with NoFollow, I don’t mind. I can play tag games, contest, meme and link to 1,000 blogs but with NOFOLLOW tags.
By default, any link that you paste in your blog post will be DoFollow, so be wise when you post a link on your blog. Because, each time you link someone or without changing anything in HTML tag, it will be in default DoFollow. If you have heavy DoFollow links outbound from your post. You are just distributing or sharing the page rank juice with the link you post in you blog post.
So, if you want to post a link in your blog, make sure they really deserve to have the backlink from you. If it is for advertisement purpose, or something that does not deserve, please change it to NoFollow link. This way, you bucket of page rank won’t drop so fast.
Love your dofollow links and use it wisely as you spend your hard earned cash.