Affiliate Guerrilla - shopping cart with built in affiliate software for Windows hosted sites. Set up your own referral program. Integrated with StormPay and PayPal so you don't even need a merchant account to start accepting payments! Supports multiple products, fixed or percentage commissions, up to 5 levels of commission per product. It can also be used as ad tracking software for your marketing campaigns! and has a built in lead management system too! Now coming with free installation.