What is Blacklists?
Many advertisers who buy advertising programmatically will use some sort of Blacklist as part of their overall buying. Blacklists are simply listings of website domain names that under no circumstances does the advertiser allow their ads to serve on that site. They are usually managed via CSV, TXT or Excel files.
The use of a Blacklist does not necessarily mean that the domain is inappropriate, it could simply mean that in the past when advertising on that website in the past, the advertiser did not obtain any clicks or conversions, thus making it unsuitable for continued advertising on it.
There are a few types of Blacklists which can be used;
Advertiser curated Blacklists
These are domains that are inappropriate, competitive or similar in nature to the advertiser.
Platform Wide Blacklist
Depending on the Advertisers’ DSP these could be made available by default in the DSP, ie irrespective if you want to buy a certain domain, the DSP will not bid on it what so ever. These are most often curated and maintained by the security teams at the DSP and frequently updated. Domains could be placed on this for unusually high click rates or impression fraud. Usually DSPs also maintain a blacklist of IP addresses within their system.
Third Party Blacklist
There are a number of Third-Party companies that maintain a universal list of domains that are unsuitable for ANY buyer. They could consist of sites which host malware, hate speech etc.