How Dynamic Ip Address is helpful for Link building. Then I need to know whether Dynamic Ip Address work much better than static ip address.
Dynamic IP's helps when you are doing some aggressive link building work to gain links to your website. It also shows to the web master/admin of the website that you are submitting links from different IP's instead of a static IP which will help you to improve your approval rate to those websites. Ingeneral admins/website owners doesn't prefer multiple website submissions from a static IP
A Dynamic IP Address simply makes it harder to be tracked in terms of mass spamming and such, it's not really needed unless you are a spammer. lol
Anyone who cares (Askimet, Google) is going to look at the subnet of your network and take actions there. You are better off using proxies.
It`s helpful if you want to submit the same site of yours to some social bookmarking site (or RSS site, or article directory, etc.) - cause if you submit your site more than a couple of times there, your static IP might get banned because of spamming. If you have a dynamic IP (means it`s changing from time to time), you can avoid that. But as WC Rocket advised, in this case you are much better off using proxies.