Release impact, before vs. after
Releases either land or they don't. The fastest way to know is to compare the same signal in the window before and the window after the ship. This pattern works for any signal: rage clicks, dead clicks, errors, drop-off, or conversion rate.
Turn 1: Find what changed
Checkout frustration: 7 days after May 10 vs. 7 days before
Got worse:
- Rage clicks on shipping-step button: 1,206 → 1,617 (+34%)
- Dead clicks on "Apply Promo": 412 → 519 (+26%)
Roughly flat:
- 404 errors, JS exceptions, console errors
Got better:
- Dead clicks on shipping address autocomplete: 247 → 198 (−20%)
Turn 2: Drill into the worst regression
3 sessions, common pattern:
- User fills in the shipping address
- Clicks "Continue to Payment"
- Nothing visibly happens for 2 to 4 seconds
- User clicks 3 to 5 more times in quick succession
- The page eventually advances to the payment step
The button does work — it has a noticeable delay with no loading state. This is a perceived-performance regression, not a functional break.
Turn 3: Size the cost
Weekly impact:
- ~1,617 users per week hit the rage-click pattern
- Conversion rate of affected sessions: 51.2%
- Conversion rate of unaffected sessions: 69.4%
- Delta: 18.2 percentage points
Estimated lost conversions: about 290 per week, assuming the gap is causal rather than correlative.
Turn 4 (optional): Set up the ongoing watch
Built a draft metric: "Shipping-step button rage clicks (daily trend)". View and save it in Fullstory to make it permanent: [metric link]
What you walk out with
A delta (+34%), a pattern (perceived-performance delay, not a break), a per-week user count (1,617), an estimated weekly conversion cost (~290), and a draft metric ready to save and watch going forward.
Behind the scenes
The MCP routes this workflow through: discover_groups with compare_to_previous=true (which returns the same-window vs. prior-window comparison sorted by biggest regressions), get_sessions, get_session_events, build_metric for the cost-sizing step, and build_metric again for the ongoing watch.