Persistence is also key. There is a lot based on aging.

--Marquita Jensen

I second you on that.... updating website and their pages is most important. Just doing off-page activities is not enough.

Directory Submission? It's useful if you send your link into a quality directory, but there are several old none quality directories which are out of Google cahce . . . I need hardly say it's a big time consumption and in top most cases the submitted link will be approved after several months of your submission date.

Blog commenting? In our days we've two essential blog engines. One of them is the Google Blogger and the other is the WordPress. The setting of linking within a comment is always NOFOLLOW. Okay this default setting can be hacked but I'm sure the average user doesn't know anything about this possibility.

A linking with NOFOLLOW attr. is a big nothing for your webmarketing.

Can you advice on how to remove the rel=nofollow attribute from blogger.com?

Login to your dashboard and click on the Layout Link. If you are already managing your blog, then click on the Template Tab.
Click on the Edit Html Sub-tab for Templates.

Now do a search for nofollow in your expanded template. You can either use your browser menu by clicking on Edit>Find in page or via the keyboard Ctrl-F. When the dialog box comes up, type in nofollow, and enter.

You should come across a line of code that looks something like this:

<dt class='comment-author' expr:id='"comment-" + data:comment.id'>
<a expr:name='"comment-" + data:comment.id'/>
<b:if cond='data:comment.authorUrl'>
<a expr:href='data:comment.authorUrl' rel='nofollow'><data:comment.author/></a>
<b:else/>
<data:comment.author/>
</b:if>
<data:commentPostedByMsg/>
</dt>

Delete the portion of the code that says rel='nofollow' and Save Your Template.

I think if you done with this you can submit your blog with this new nofollow feature to a dozen of directories which has a NOFOLLOW style blog collection.

I found the same solution on web, but anyway, thanks for your help.

Basically google is your best friend, if you google your industry and add directory on the end, its your best bet. You will get some leads as to places where you can add your site. These will be beneficial because its your industry and applicable to your business thus trustworthy to search engines.