not sure if this will go in business practices or advertising :
Say i have a regular corporate site explaining my company such as gratisinternet.com or redventures.com type of sites. Do you think it is bad business to have one of the tabs on the sitemap say "articles" then will link you to a ton of articles i wrote explaining different marketing techniques such as SEO , lead generation and other types of advertising and then put affiliate ads and google ad words on the articles?
If your company is selling a product or service, like those examples you linked, then putting a bunch of articles with ads on them on the same site would be strange. If the articles are meant to attract people to your site in order to help sales, then you don't want ads on them sending people away from your site, potentially to competitors. If the articles were written solely to attract eyeballs to ads, then they don't belong on the same site at all.
If the articles on your site are on individual pages of your site, then they should appear as individual links on your site map. If articles are not on your site, they have no place on your site map. The purpose of a site map is to show your visitors what is on your site, not what is on another site.