You should implement conversion tracking before you spend a dollar on ads or launch any structured marketing campaign. If you're running Google Ads, Meta ads, or even organic SEO with content targeting specific buyer intent, you need to know which clicks turn into form fills, purchases, calls, or downloads. Without conversion data, you can't calculate cost per acquisition, optimize bids, or justify budget to stakeholders. Conversion tracking becomes non-negotiable in these situations: running any paid search or social ads, testing landing page variations, tracking lead gen forms or e-commerce transactions, measuring phone calls from click-to-call buttons, or attributing revenue to organic traffic sources. At Ottawa SEO Inc., we set up Google Analytics 4 goals and Google Ads conversion actions during onboarding because retrospective data doesn't exist—you can't reconstruct what you didn't measure. The technical setup varies by goal type. E-commerce conversions fire when a transaction completes and pass revenue values. Lead forms trigger on thank-you page loads or button clicks. Phone call tracking requires dynamic number insertion or Google forwarding numbers. For local businesses, store visit conversions link online clicks to foot traffic via location data, though this needs scale to be statistically valid. Common mistakes include tracking only macro conversions like purchases while ignoring micro conversions such as email signups or PDF downloads that indicate buying intent. Also, failing to exclude internal traffic skews data—your team's test submissions aren't real leads. Use IP exclusion filters and UTM parameters religiously so you can segment by campaign and source. If you're purely brand-building with no immediate conversion goal, tracking may feel less urgent, but even then you should monitor engaged sessions, scroll depth, or video plays as proxy metrics. The cost of not tracking is simple: wasted spend on underperforming keywords, inability to scale what works, and zero accountability when the finance team asks for proof of ROI. Start tracking conversions today, not when you feel ready.