Don't waste your money on tag and ping
! You can do this for free. This is the big secret the so called guru's don't want you to know about.
First before you decide to write your blog post you should go to Technorati and find some of the popular tags and write posts on these topics.
If you use Blogger.com you can just add this line to the end of every post.
<a href="http://technorati.com/tag/[tagname]" rel="tag">[tagname]</a>
Make sure you replace [tag] with a your relevant keyword.
Your next step now is to ping your tags!
That is all there is to it folks.