Before Facebook arrived, the ability to target very specific segments was incredibly difficult.

For example, if you had wanted to target all mums with a two-year-old child in the UK, you would be looking at some daytime TV, weekly magazines, and outdoor in specific nappy valleys.

Your chances of reaching your target segment would be higher than ‘spraying and praying’, but not by much. You would likely also reach lots of other people outside of your target segment and hence waste lots of money.

Facebook is the first advertising channel that completely removes this blind spot. It means you can employ the marketing practices of segmentation with razor-sharp precision.

Facebook means that if your strategy is to target liberal conservatives who might be swayed to vote for Brexit with messaging about Turkey joining the EU, you could implement this without much bother. We’ve seen the full effects of this kind of micro targeting from the Vote Leave campaign.

This kind of approach only works if your segmentation is sophisticated enough to split the attributes of potential customers in a way that’s truly relevant to your brand. For example, postal address, annual salary and family status will matter to a local high-end bakery, whereas attitudes to credit and short- and long-term financial goals will matter more to an online credit broker.

How you split your segments will dictate your strategy, and often be the root cause of success or failure.

Before Facebook, you would likely need to decide upon one target segment and focus your media buy to avoid wastage. Now, it’s possible to create campaigns for all your customer segments and test different messages against each. This was never possible; you can’t do this with any traditional media channel.

It’s also now easier to pay more for customers who are worth more to you. Simply hook up your CRM platform to Facebook, create lookalikes for each of your target segments, set bids and you’re good to go.

What I hear a lot is that you don’t need to target any more because you can reach everyone in your potential customer universe much more easily. I disagree with this.

I think segmentation and targeting online are now more important because you can do much more with the data. Vote Leave’s segmentation was sophisticated enough to identify who might be swayed and by what message. They could also exclude anyone they deemed hard to convince.

A lot of digital marketers are not experienced in customer segmentation because it wasn’t required to optimise campaigns. It is now.

Econsultancy runs a three-day CRM workshop. Subscribers can also download Econsultancy’s report, Navigating Brexit: A Provisional Guide for Marketers and HR Talent.