Conversion

A conversion is any user action a business defines as valuable enough to track and optimize toward — a purchase, signup, lead, or app install.

"Conversion" is a placeholder word, not a fixed action — its meaning is whatever a team configures it to be in their ad account or analytics tool. An ecommerce brand's conversion is a purchase. A SaaS company's might be a demo request, a trial start, or a paid upgrade, tracked as three separate conversion events at three different funnel stages.

The most common measurement mistake is optimizing ad platforms toward a shallow conversion event (like "Add to Cart" or "Lead") because it's cheap and easy to generate volume on, while the business actually cares about a deeper event (a completed purchase, a paid subscription) that the algorithm was never told to prioritize.