Alexa - focus on traffic - does it hurt me?
 

I run a Wordpress site and I have registered my site with relevant webmaster tools: Google, Bing and Alexa.

Now I've heard that Google is more biased towards backlinks and internal links in it's reward system, whereas Alexa is more biased towards traffic.

Is it wise to rate my site through Alexa, since traffic will always be fairly low (which is related to my niche or branch)?

Is there detailed information available on the comparison of ranking systems of Google and Alexa.

No, Alexa rank is a overall traffic rank. This will not hurt your search engine ranking. Just focus on your website ranking. Once your ranking will be increases, your website traffic also increasing. Becasue of this your alexa rank will be reduceing. Then just focus on your website ranking.