Link Development in several sites with same IP? let say if i do social bookmarking in 100 sites but those site have a same IP then it would count as a single link or 100 links?
IP diversity is important in link building. its not how many links you get credit for, its how much weight each link carries. if all 100 bookmarking sites are on the same IP, then most likely they will be low quality and new or relevantly new bookmarking site network. you don't expect to get good value form such backlinks. why not pay someone few dollars and get 100 bookmarking links from 100 unique IP addresses?
In link building, IP address is counted.... so you won't get much benefit, but you would get benefit more than one link too.. Try to use unique IP address, it is good for link building purposes as you would be able to build natural links..