I've seen it done on some websites. Typically as a partnership with an online shop that sells things of interest for the website audience.
It is probably very effective if you have an audience with well targeted interests. For example a site about espresso coffee may partner with a shop that sells high end espresso machines and specialty coffee.
However, it is much harder if a website has a broader audience. A news network probably has no clue about what visitors want to spend their money on, so either they use an ad network that does the targeting for them, or they are limited to less beneficial generic partnerships.
It is probably very effective if you have an audience with well targeted interests. For example a site about espresso coffee may partner with a shop that sells high end espresso machines and specialty coffee.
However, it is much harder if a website has a broader audience. A news network probably has no clue about what visitors want to spend their money on, so either they use an ad network that does the targeting for them, or they are limited to less beneficial generic partnerships.