Originally Posted by pradaboy

there has been talk that this is not only for new sites, but that Google uses an average of time and quantity it takes other sites in your category to obtain natural links and if you go over this they will put the new links in a sandbox and thus they will not count for your PR / link popularity yet.

Of course it's not certain that this is true but it is a logical step at this time when purchasing oneway links and doing massive link exchanges is getting more and more common