A very interesting and intriguing part that i found while researching on google patents for ranking As per point 59, if links are there for short time then you can get penalized, so this means it is not a good idea to get forum/community links, since if the webmasters decide to delete a lot of them, then you can be in trouble, since your linkage data will show lot of movement of links in (+) and (-). So if you are creating profiles backlinks, then manage to post / contribute to the community and stay within the webmasters radar. As per Point 60, the page from where you are getting backlinks also needs to be updated over certain period of time and then penalizing or boosting the ranking if the content is not updated or vice-versa. This also means getting some profile links will do no good, but you need to post / contribute content and your link needs to get fresh content around it too.