C.Rebecca

You mean to ask if the technique is useful or not? It’s an excellent SEO technique if done properly i.e. commenting intelligently (adding value) on niche related blogs.While commenting on a no-follow blog might get you streams of referral traffic, commenting on a do-follow blog brings you backlinking credit.

Blog commenting tips:
-Always comment on niche related blogs
-Comment intelligently
-If at all possible, use your real identity and photo
-Read previously posted comments on the thread
-Make your profile link point to an appropriate place

The technique works great with me, I use Keyword Country to find traffic-pulling, high authority, related blogs to comment on...I am all for it!

Probably,
-You're not really ranking (you are getting personalized results)
-Your Keywords are not popular enough to be clicked

Firstly, you need to test your keywords for popularity. You may use Google analytics to pinpoint keywords that bring you traffic.

Secondly, its important you increase your presence on social media channels (by participating on forums, social networking sites, social bookmarking sites, blogs etc...)

Penguin is a fight against all existing forms of webspam including link spamming/ trading, aggressive overuse of exact match anchor text, submitting to low quality article/ blog directories etc.

So make sure:
- You have variation in your anchor text
- You are not buying/ exchanging links
- Your website is compelling enough to pull natural backlinks

Your Alexa ranking has got absolutely nothing to do with blog commenting, link exchange, blog hosting sites or article posting...It is a flawed system and can be easily increased by installing Alexa toolbar on your system and visiting your website few times in a day. Hence it’s not an important metric and you need not lose sleep over it!

- Write content that is deliberately designed to attract links towards it
- Submit RSS feeds to feed directories
- Submit website to social bookmarking sites
- Participate in dofollow social networking sites and related communities
- Write guest posts for blogs related to your niche
- Monitor link building strategy of competitors

I use ‘Keyword Country’ to design my link building strategy around traffic pulling keywords and to monitor link-building strategy of my competitors. Pretty satisfied.