How to Put Ads on the Side of Your Tumblr

1. Log in to your approved Google AdSense account and click on the 'My Ads' tab. A list of previously created ad units displays, showing when they were last edited and whether they are active.
2. Click on the 'New Ad Unit' button. All of the options for your new ad will be displayed.

3. Fill out each of the required fields. Name your ad and choose the size that best fits your Tumblr blog. The most common size for a sidebar banner is the sidescraper option.
4. Create a new custom channel on the options screen. This makes your Tumblr ad campaign easy to track, helping to monitor the performance of your AdSense ads across multiple websites.
5. Click 'Save and get code.' A small screen pops up with JavaScript code specific to the ad you have just created.
6. Copy the JavaScript within the window by highlighting all of the text and clicking 'Ctrl-C.'
7. Log in to your Tumblr account and click on the appropriate blog name within the drop-down menu on your dashboard. More options will display, including the ability to edit your theme.
8. Click on 'Customize' to bring up the settings for your particular Tumblr, then click on 'Theme' within the header and 'Enable custom HTML'. The editable HTML for your Tumblr theme now displays within the window.
9. Place the Tumblr code in the appropriate place within your theme's HTML by clicking on the location you wish to paste it to and typing 'Ctrl-V' If your theme has a sidebar, cross-reference with a live version of your Tumblr so that you can identify where to place your ads. A common location is after the 'About' section within your sidebar. Use 'Ctrl-F' to find specific locations within the HTML.