Lead attribution, explained
Lead attribution answers a simple question with an awkward answer: which marketing brought this lead? A person might see an Instagram ad, search your name a week later, read a blog post and finally fill in a form. Attribution is the rule you use to give credit — to the first touch, the last touch, or some share of each.
For most small sales teams, last-touch attribution recorded on the lead is the practical starting point: keep the source, the campaign and the form the lead converted on, plus the UTM tags and click IDs from the landing page for website leads. That alone answers most budget questions, because it shows which channels produce enquiries and which of those enquiries turn into deals.
Attribution breaks when the data is not captured at the moment of conversion. If leads are copied into a spreadsheet by hand, or a form strips its URL parameters, the source is lost for good. Capture it automatically on every lead, keep your own source names consistent, and compare leads by source with deals won by source before moving budget between channels.