I can't sign in to ContactMonkey's sidebar in Gmail

Follow these instructions to get the sidebar to reappear:

1. In the Chrome address bar, enter chrome://settings
2. In the left pane, select Privacy and security
3. Click Third-party cookies
4. To enable cookies, select Allow third-party cookies

Note: if Block third-party cookies is enabled, then go to Allowed to use third-party cookies at the bottom of the page. Click on Add, then add contactmonkey.com to the list.