What is a blocklist?

A blocklist is a list of websites that advertisers determine their creative will not appear on, due to the fraudulent or inappropriate nature of the content, which could harm their brand reputation. Blocklists are used to ensure content is reaching the correct audiences. Through creating these blocklists, organizations gain a clear understanding of what is and is not acceptable content for advertisers.


Other types of blocklists: 

Blocklists apply to other forms of marketing as well, such as email marketing and keyword planning. These types of blocklists protect users from spam and ensure that the right audience is consuming the company’s content. 

Email marketing blocklist

A blocklist for email marketing is a real-time list of websites or servers that are blocked because spam emails are sent from them. Email blocklists, or blacklists, are used by internet service providers (ISPs) and free email providers to prevent spam from coming into the systems. Spam is considered unwanted emails from advertisers or emails that could contain downloadable viruses. Blocklists help prevent these types of emails from entering users’ email boxes. 

Before an email can be sent to an inbox, the server sending the email is compared to the blocklist. The email is sent to the inbox if the server doesn’t match any addresses on the blocklist. If it does match the blocklist, then that spam email is rejected and sent back to the sender.

Keyword blocklist

A keyword blocklist is a list of keywords that an advertiser or company deems inappropriate for a website, blog post, or article to be associated with. Keywords are the words or phrases that are entered into a search engine to populate results. A company that exclusively markets dog toys could put the keyword “cats” on the blocklist. This would allow for this company’s web page to not populate when the term “cats” is searched. As a result, the company’s ads would only show to the desired customer who owns a dog. This enables marketers to ensure their marketing budget is reaching the ideal audience. 


Benefits and disadvantages of blocklists: 

Through the implementation of blocklists, the number of spam websites and emails have reduced considerably. This allows users to find desired content quicker and decreases the need to search through irrelevant emails or websites. Blocklists must be updated frequently as there are constant changes in audience opinions. These lists need to be consistently monitored to ensure accuracy.  Blocklists are great tools to utilize to allow ideal audiences to receive the correct information.