Initial sales of Windows 7 were 234% higher than Vista's first few days of sales in the US, according to market research firm NPD Group. Although Windows 7 sales were up by over 200%, revenue growth was 82% up over Vista. The smaller growth of revenue has been attributed to early discounts for pre-orders and not enough advertising for the high-end "Ultimate" version of Windows 7. Stephen Baker, vice president of industry analysis at NPD said that “Microsoft’s program of early low-cost pre-sales, high visibility marketing, and aggressive deals helped make the Windows 7 software launch successful. In a slow environment for packaged software Windows 7 brought a large number of customers into the software aisles.” The top-selling SKUs of Windows 7 were Home Premium Upgrade, Pro Upgrade and Home Premium Family Pack (3 User) Upgrade at an average selling price of US$76, US$147 and US$149 respectively. It seems that Windows 7 has brought in all the customers wanting a fresh start with Windows and what's more, the attractive prices make it even harder to resist Microsoft's sleeker, faster and more minimalist OS.