Sgt_Kickaxe - 7:03 am on Sep 9, 2010 (gmt 0)
#1 - Create solid content and know which keywords/pages your traffic is coming from.
#2 - No, it's not, the best links are free and given based on merit, not cash.
#3 - Your traffic level changes, if it doesn't the change likely didn't impact you.
#4 - Save yourself the trouble, Google will list you in time.