You might have heard the term ‘hashing’ a few times but still not be totally sure what it means in a marketing sense. It’s ok, do not worry! Here is an outline of what it’s all about and why it is so important for you.

Facebook, Twitter and Google allow you to make the most of your active data.  By using your audience’s email addresses, these platforms can create audiences and lookalike audiences; this is where hashing comes in. Simply put, hashing is the process of turning these email addresses into numbers to protect both your audience’s data and the platform’s data.

For example, when you upload a list of email addresses into Facebook, they are each converted (hashed) into a unique number; this happens on your computer and the email addresses never leave your server, just the hashed number. Facebook also hashes its profiles and stores them in a second list of numbers. These two lists are compared, and if there is a match then you can target this user – still not knowing specifically who they are.

So for example, you can target your list of 1000 prospects on Facebook by uploading their email addresses, which will then be hashed and compared with Facebook’s profile database. From that, let’s say 600 profiles match the email data you uploaded. You can target these 600 of your current prospects on Facebook. You can drill down further, and split your audience into custom audiences – for example: males, aged 18 – 25, with an interest in politics.

You can also create lookalike audiences. Facebook will look at the age, gender, interests and locations on your prospects profiles, and find similar profiles for you to target.

The hashing process protects your College or University under the Data Protection Act as well as allowing you to target users much more effectively.

Want to know more about how hashing can improve your marketing activity? Get in touch.

Article by


Matt Payne

Senior Marketing Executive