morpheus83 - 6:46 am on Jul 29, 2011 (gmt 0)
If you have a considerable amount of US based traffic then VibrantMedia will work much better for you. I have been using Kontera in the past and then made the switch 2 months back and the results have spoken for themselves. The factors to take into consideration are the amount of traffic you get from Search engines and direct traffic. The former being the key factor for better revenue in this case.