1. Access the advertisement code you want to put on your Tumblr page and copy it. This is typically done by logging in to an affiliate account, such as your Amazon Associates page, generating the promotion and then copying the code that automatically displays. See your affiliate account's 'Help,' 'Support' or 'FAQ' page if you need more information on this process.
2. Log in to your Tumblr account and click the 'Customize' link.
3. Click the 'Theme' option in the menu and then click the 'Use custom HTML' button.
4. Scroll through the code that displays until you see the '
' tag, which is typically 3/4 of the way down on a Tumblr theme. Paste your advertisement code underneath this tag to make it visible on your blog. If you want the offer to appear at a specific place on your blog page, find that text in the blog code and then paste the offer code near this area.
5. Click the 'Save Close' button, then click the name of your Tumblr blog on your Tumblr dashboard page to see your ad.