Amazon derives many of its sales from third-party sellers who sell products on Amazon (around 40% in 2008).[263] Associates receive a commission for referring customers to Amazon by placing links to Amazon on their websites, if the referral results in a sale. Worldwide, Amazon has "over 900,000 members" in its affiliate programs.[264] According to W3Techs the Amazon Affiliate Program is used by 1.2% of all websites, and it is the second most popular advertising network after Google Ads.[265] It is frequently used by websites and non-profits to provide a way for supporters to earn them commission.[266] Amazon reported over 1.3 million sellers sold products through Amazon's websites in 2007. Unlike eBay, Amazon sellers do not have to maintain separate payment accounts; all payments are handled by Amazon.