Insert a PayPal button in a public-facing webpage: SharePoint 2010.

You can provide a PayPal button on a webpage in your public-facing website. PayPal is an online payment service that provides users with a secure way to send money to you without leaving your site. This form of payment can speed up the delivery of products and services, and also provide secure transactions for both buyers and sellers.

 Note   

• Before you can add a PayPal button to your site, you must have a PayPal account. To set up a PayPal account, visit the PayPal site.
• The procedures in this article apply only to public-facing websites and webpages.

When you insert a PayPal button, it’s added in line with existing content:

1.      In your PayPal account, create a new button, and then select and copy the HTML code for your PayPal button.

2.      Open the website in your browser, and then click Member Login on the home page.

3.      On the top-navigation bar in the site, click Website.

4.      In the website, click Web Pages on the Quick Launch.

5.      Click the Pages tab on the ribbon.

6.      Select the check box next to the webpage where you want to add a PayPal button, and then click Edit.

7.      In the webpage, click to locate your cursor where you want to add the PayPal button.

8.      Click the Insert tab and then, in the Gadgets group, click PayPal.

9.      In the PayPal dialog box, paste the HTML code for your new PayPal button.

10. Click OK.

Reference: http://office.microsoft.com/en-us/office365-sharepoint-online-enterprise-help/insert-a-paypal-button-in-a-public-facing-webpage-HA101848175.aspx