Conversion tracking in Facebook Ads is the system that records when someone completes a valuable action on your website or app after interacting with your ad. You define what counts as a conversion—could be a purchase, lead form submission, add-to-cart, page view, or custom event—and Facebook tracks when those happen. You implement tracking through the Meta Pixel, a JavaScript snippet you add to your site, or the Conversions API, a server-side method that sends event data directly from your backend. The Pixel fires when someone lands on a page or completes an action; the API is more reliable because it bypasses browser restrictions like ad blockers and iOS privacy settings. Most serious advertisers now run both in parallel for redundancy. Once tracking is live, Facebook's algorithm uses conversion data to optimize your campaigns. If you tell it to optimize for purchases, it learns which audience segments and placements actually buy, then shifts budget toward those. Without conversion tracking, you're flying blind—measuring only clicks or impressions, which correlate poorly with revenue. Tracking also powers your reporting. The Ads Manager dashboard shows cost per conversion, conversion rate, and return on ad spend. You can break this down by ad set, creative, or audience. If a campaign shows 50 link clicks but zero purchases, you know the landing page or offer is the problem, not the targeting. Key setup details: You install the Pixel via Google Tag Manager or hardcode it into your site header. Then you configure standard events like Purchase, Lead, or AddToCart, passing parameters like value and currency. For e-commerce, dynamic product catalogs let you track which specific SKUs drove sales. The Conversions API requires a developer or a platform integration—Shopify, WooCommerce, and most CRMs have one-click connectors. At Ottawa SEO, we treat conversion tracking as non-negotiable. A client running Facebook ads without it is burning money on volume metrics that don't correlate with business outcomes. We typically set up Pixel plus API, verify events in the Test Events tool, and build custom audiences from converter behavior to feed lookalike targeting. The tracking infrastructure is the foundation; creative and targeting come second.