The chart displays the US Social Media Advertising Average Cost per Engagement (USD) from 2015 to 2025, illustrating a significant and continuous upward trend in cost over the decade. The cost per engagement started at its lowest point in 2015 at 0.18 USD. It then saw a steady increase each year, rising to 0.20 USD in 2016, 0.22 USD in 2017, 0.24 USD in 2018, and 0.26 USD in 2019. The cost continued to climb, reaching 0.28 USD in 2020, 0.30 USD in 2021, and 0.32 USD in 2022. The upward trend is projected to continue with 0.34 USD in 2023, 0.36 USD in 2024, and peak at 0.38 USD in 2025. This represents more than a doubling of the cost per engagement over the ten-year period ($\mathbf{0.38 \text{ USD} - 0.18 \text{ USD} = 0.20 \text{ USD}}$ increase), reflecting growing competition and platform maturity in social media advertising.
| Labels | Average Cost per Engagement (USD) 2015–2025 |
| 2025 | 0.38 |
| 2024 | 0.36 |
| 2023 | 0.34 |
| 2022 | 0.32 |
| 2021 | 0.3 |
| 2020 | 0.28 |
| 2019 | 0.26 |
| 2018 | 0.24 |
| 2017 | 0.22 |
| 2016 | 0.2 |
| 2015 | 0.18 |
