direct sales is a sale made between a publisher and an advertiser.
Direct sales is also known as:
In a mediation, direct sales generally generate the most revenue and is therefore the first sale done in a classic waterfall method but with the advent of header bidding, it may be placed in second position.
Direct buys are almost always priced in fixed CPM rates, where the inventory is sold in bulk and all impressions are essentially priced the same (e.g., 10 CPM, or 10 per thousand ad views).
You can see if an ad network is an account of the direct type in the ads.txt file.
Prebid and TAM are considered direct, because they don’t handle payment.
programmatic direct is a direct sales but without the human factor.
Example of direct ad order properties: