You may have a situation where you've created one or more free bundles and you want members to be able to select which one(s) they want applied to their account. If you want to allow a customer to apply a free bundle to their account just use the following:
<a href="[MM_Member_Link type='freeBundle' value='10' redirectUrl='http://yourdomain.com/thankyou.php']">Accept this Free Gift</a>
The result is that when a member clicks on this link, the free bundle with an ID of 10 will be automatically applied to their account and they'll be redirected to the thankyou.php page. The redirectUrl parameter is optional. If you don't provide this parameter the page will simply refresh following the bundle being applied to the member's account. Read this article to learn more about the MM_Member_Link SmartTag.