Advertisements are not the same as spam, so you can include ads in your email campaigns if you choose. However, the ads should be included as an addition to your content and not be the bulk of your email.
Here are some things to keep in mind before you place ads in your campaigns.
Use static images for ads in your campaign. Animated GIFs and Flash are not guaranteed to work in all email clients. If you'd still like to use Flash or animated GIFs, test your email thoroughly before you send it to your audience.
The links for Google's DoubleClick ads often break when used in Mailchimp campaigns, or you might not be able to track them. This is due to the way the DoubleClick URL interacts with our click-tracking redirects.