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Marks & Spencer - Uncovering the value of Facebook ads for customer acquisition

by Stephanie Boland

The British retailer used custom conversions and a conversion lift test to unlock insights about how efficient Facebook ads are at acquiring new customers, and discovered an 11% lift in incremental purchases by net new customers.


A byword for quality

Founded in 1884 by Michael Marks and Thomas Spencer, Marks & Spencer (M&S) is a major international British retailer of high-quality food, drink and clothing, with 959 stores across the UK, and a significant online presence.


Insight into new customer purchases

M&S wanted to take advantage of Infectious Media’s status as a Facebook Marketing Partner for Agencies, and its access to the latest measurement research initiatives available to premium members—in this case, a net new customer incrementality test.


Evolving Facebook measurement for ads

M&S had already worked with Infectious Media on direct response campaigns. For this experiment, the Facebook Marketing Partner created custom events from M&S’s own data to separate new customers from repeat customers. Then, they partnered with Facebook to run a conversion lift test that used these custom conversions.

Thanks to this net new customer incrementality test, M&S gained better insight into online purchases and was able to determine how many incremental online purchases were made overall, along with additional insight into whether or not the customer was new or repeat. By quantifying the number of new customers, it found that existing customers were a stronger source of new purchases than the brand had previously realised. The test results also showed that its net new customers were in a younger age range, which helped validate its strategy to expand its target audience to attract new customers.


Top marks

The lift test results showed a strong overall return on ad spend, helped M&S quantify new customers, and also shed light on a new customer demographic:

- 2.6X return on ad spend

- 1.4% lift in incremental purchases by new customers

- 11% of incremental purchases came from new customers

- 5.1% lift in purchases from existing customers

- 2X higher incremental revenue from existing customers than new customers

"Proving the value of social marketing and how best to measure its true performance is an ongoing topic internally, meaning running a study such as this was crucial and allowed us to demonstrate the impact Facebook can have on customer behaviour—specifically its strength in driving new customers. The results from this beta test have since assisted us to change our strategy and secure budget with the sole focus of driving new customers to M&S."

~Liv O'Neill Paid Media Manager, M&S

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Marks & Spencer