I'm using Efficient Era for my Amazon seller account and it is such a time saver. The features are great and the price is very affordable. It's a must have if you sell on Amazon! I really like the VAT invoice features that allow your customers to generate their own purchase orders (based of real orders of course). To be franck i havent used all the features and services included in my package yet like automated follow up emails, but i will sure do soon.