How to Measure Lead Source ROI: Which Channels Actually Convert

Ask most business owners which channel is their best, and they'll name whichever sends the most enquiries. But volume isn't value — a channel that floods you with tyre-kickers can cost more than one that quietly sends serious buyers.

Track the full funnel, not just leads

Real ROI needs three numbers per source: leads, conversions, and revenue. A source with fewer leads but a high close rate often wins on profit. If you only count leads, you'll keep overspending on the loud, low-converting channels.

Attribute every lead to a source

This only works if every lead is tagged with where it came from — automatically, at capture. Manual tagging is inconsistent and quickly abandoned.

Watch cost per conversion, not cost per lead

• Cost per lead flatters cheap, low-quality channels.
• Cost per conversion tells you what a customer actually costs.
• Revenue per source tells you where to reinvest.

Review monthly and reallocate

Once a month, look at conversions and revenue by source and move budget from the weak channels to the strong ones. Small, regular reallocations compound into big gains.

How ASH helps

ASH tags every lead by source automatically and reports conversions and revenue by channel — so you can finally see which sources produce sales, not just enquiries.