Can you checkout the Device Type contribution for your Campaigns? If it is Mobile, might be because they have come from Mobile Applications like Facebook, Twitter, Instagram to reach the Campaign Landing page loaded in their Browser. While customer switch between Application to Browser, the details will be empty and bucketed under Typed/Bookmark. Thus it is important to tag your Campaigns with proper query string parameters and bucketed either under Paid or Organic. Cheers!
If you are looking into referrer, referrer type, and referring domain report to compare traffic source it may be misleading. e.g. Adobe will record referrer type as "other websites" (your campaign of affiliate site or may be email) in first hit of the visit but if user leaves site and return before visits ends by typing site url directly...it will overwrite referrer type with "Typed/Bookmarked".
Note : The referrer, referrer type, and referring domain are set on the first hit of the visit, or during a visit when the referrer is external (for example, if a visitor leaves your site, uses a search engine, then returns to your site before the first visit expires). These values are set at the same time and persist across the visit.