Amazon has launched two hosted e-commerce payment services called Checkout and SimplePay for online retailers. Both services will compete directly with Google's Google Checkout and eBay's PayPal respectively.

Amazon's Checkout offers a complete checkout solution that features a "one-click" payment option and tools for management of shipping charges, sales tax, promotions, and post-sale activities. Amazon account holders can purchase from merchant's website using information of their Amazon account and other websites powered by Amazon. Google introduced Google Checkout way back in 2006 but couldn't impress merchants and customers. See more about Checkout here.

SimplePay offers a spectrum of payment options for purchases, donations, and marketplace transactions. Likewise, it also allows users to use their Amazon.com account's payment information.

Being PayPal's direct competitor, it's uncertain whether people can use SimplePay on eBay. Check more about SimplePay here. Online retailers have yet another option for using the online retailer's service for their website to attract more customers.

Now it's up to Google and eBay to see whether Amazon's new services pose any real threat to them.