Quote:
Originally Posted by Apoorva
Hi,
I will provide you the source link also but don't want more infractions, thus telling only the name, I have read articles and participate in forums to get this figure. Alla re suggested the figure of 2-5 %. therefore, I put it here. I think, the information provided by the Google at top results is trust-able.
Well, it is like that:
30 instances in the 900 words of article is 2%. I hope I satisfied you with this answer.
You will not (and have not) receive an infraction for giving a link to source that is relevant to the topic - especially as I asked you for one

Sources are important because they are the difference between stating an opinion and stating an opinion that is supported.
I have found the source you are referring to:
http://hubpages.com/forum/topic/56076
and this is simply a discussion, not a source. A source is the origin of where something that is discussed comes from, for example a statement from Google.
On the subject of keyword density, there is a video from Matt Cutts regarding keyword percentage:
http://www.youtube.com/watch?v=Rk4qgQdp2UA
I don't believe everything that Mr Cutts says, especially when he is being deliberately vague. But in this he specifically says that there is no ideal percentage for keyword density and I would consider this to be an authoratitive source.
Just because something is repeated often, it does not make it true.
Regarding the "30 instances in the 900 words of article is 2%", that is 3.33% I believe.