Links are not just! They are important for both the site (A), they link to, and to the site (B) that is linking. Let's take a look at A's situation first:
Why the Anchor Text is important to the Site that is being linked to
A is a homepage, and the owner would like it to be found in the search engines if people write “the root of all evil”. Yup, an interesting manner of speech – others might have thought about boring things like “nice webdesign”, “the best redwines”, “the soft paws of Fido” or something completely different.
It will not be of much help for A, if he's found by the word “here”, which is the case for the company Adobe.
I A wants his page to be found by “the root of all evil”, he should make sure that people uses the exact same words, when they are linking to him, i.e. with a link like this: <a href=”http://www.a.com”>the root of all evil</a>
Why the Anchor Text is important for the Site that is linking
Search engines are looking at the content of the linking site too, i.e. B's site, and they will especially look at titles (where you use <h1> etc.), links etc.
If B is a fool and uses the text HERE, when he makes the link, the search engine will not get much information from that (neither will the blind by the way). Search engines are basically stupid. They know only what you tell them, volunterely or unvolunterely.
So if B tell the search engine that “the root of all evil” is www.a.com, the search engine would go “Wow! I'm on to something here! Woah!”
And then it has learned something about B's page, which it will use to choose which ads to show, if the ads are contextual like AdSense.
Now, What can you use all that for?
Your mission, should you decide to accept it, is to make people use intelligent links to your site.
You can premake a code that they can copy and paste to their own site. If they bother. Few do. Or you can do something really smart. You can make people stand in line to link to your site the right way, and you will be able to punis them (he, he) should they make a mistake.
Grap this Idea
This is the idea that “the root of all evil“, alias John Chow, made up. He has joined up with a sponsor, 1234pens.com, who makes “promotional pens“. He's offering a prize, a Nintendo Wii amongst those, who write a blog posting, link to his competition with the words “the root of all evil” and link to the homesite of the sponsor with the words “promotional pens”, just as you can see, I've done. After that you have to send him the link to your blog posting, and you're in the game. It doesn't matter which language your blog is written in.
Now thousands will stand in line to link with the precise words John Chow wanted. In a short while we'll see who's number 1 on Google, when you search for “the root of all evil” 😉