What are cookies? : Wikipedia
A cookie, also known as an HTTP cookie, web cookie, or browser cookie, is a piece of data stored by a website within a browser, and then subsequently sent back to the same website by the browser. Cookies were designed to be a reliable mechanism for websites to remember things that a browser had done there in the past, which can include having clicked particular buttons, logging in, or having read pages on that site months or years ago.
When you send a friend a referral link, we save your user id to their computer temporarily. This is so when they sign up we know it was you that referred them. We can award you both the 1 months free TopMembership.