Short answer
For their own party pages, largely yes. For leaders' pages, no: they earn most of the engagement but get little of the money.
What the evidence shows
- For 25 British party and leader pages, the study joins CrowdTangle engagement (March 2016 to September 2020) with lifetime Ad Library spend (October 2019 to October 2026).
- Among the 12 party pages, advertising spend follows organic engagement closely (Spearman rank correlation 0.76).
- Labour's leader's page took 75% of its leader-plus-party engagement but 36% of its spend; for the Conservatives the figures are 68% and 7%, for the Liberal Democrats 16% and 1%, and for the SNP 51% and 2%.
- Nigel Farage's page comes closest to being paid for in line with its engagement.
Caveats
The two datasets only partly overlap in time, so the paper describes a pattern across pages, not the effect of spending on engagement.