Case Study: Sierra Club achieves 830% increase in monthly donations with Optimizely

Sierra Club turns one-off donors into monthly donors

Sierra Club, the long‑running environmental nonprofit, needed to boost online conversions and convert one‑time givers into reliable monthly donors to stabilize year‑round revenue beyond the typical year‑end surge. Their digital team focused on experiments to raise donation lift and prove ROI to stakeholders.

Using Optimizely Web A/B Testing they ran simple, targeted experiments — adding a “cover processing fee” checkbox, a 2‑step email capture on Facebook ads, swapping one‑time asks to monthly asks, simplifying form fields and repositioning key content. Outcomes included an 830% increase in monthly donations since 2015, a single email‑capture test worth about $200K (the fee checkbox added ~$175K), monthly donor revenue rising from roughly $200K to $1M over two years, and a 14% lift in monthly gifts from simplified forms.

Sierra Club