You can literally add sponsor and advertiser information to almost any type of content that has a description field and allows for text input. For example, you could add, "This program was brought to you by SPONSOR NAME and SPONSOR LINK" in the "About Episode" field section within your episode content (individual show archive page/podcast episode page). Almost all content with a long description field has copy and paste ability, so you can add content from another website. You can also change fonts, sizes, colors, etc.