A quick primer
The official mechanism built specifically for this scenario is the conversion window. The setting is ideal for businesses selling products with a a longer buying cycle the standard 30-day window. Google is directly acknowledging that the default setting doesn't suit every business model, and provides a dedicated official tool for long cycles instead of forcing everyone into one standard.
Extending the window has a direct consequence: a longer conversion window lets you find keywords earlier in the path to conversion within Attribution reports. That means with a short window that doesn't fit the business, clicks tied to a real sale that happen outside 30 days simply don't get counted as leading to a conversion, which systematically understates ROAS for campaigns that engaged early in a long B2B cycle relative to their real contribution.
What to check before you touch anything
- What conversion window is currently set for the relevant conversion actions. Compare it to the business's actual, typical decision cycle length.
- Is there data on the real distribution of time between a click and a conversion (conversion lag reporting). That tells you what window is actually needed, rather than a guess.
- Is attribution configured for genuinely long paths. Even a more advanced attribution model can't credit a conversion that happens outside the window.
- Does the business have earlier, intermediate conversion actions (a demo request, a content download, a call). These can serve as a faster signal for Smart Bidding without waiting for the final deal.
- Is campaign performance being judged too early after launch or a change. A long sales cycle already requires more time to accumulate statistically meaningful data.
Possible approaches
- If the real sales cycle is notably longer than the current conversion window, extend the window to a value closer to the actual cycle, instead of the default 30 days.
- If the business has intermediate conversion actions earlier in the funnel, use them as a primary Smart Bidding target alongside, or instead of, the final deal, since they give the model a faster, more frequent signal.
- Don't judge campaign performance over short periods. A long sales cycle requires more time for a fair evaluation than typical ecommerce.
- If extending the conversion window reveals that campaigns previously judged inefficient are actually engaging early in long, successfully closing deals, revisit any budget cuts made based on the earlier, understated ROAS.
- Regularly reconcile the real sales cycle length (through conversion lag reporting or CRM data) against the conversion window setting. The cycle can shift over time, and the setting should be revisited accordingly.