An MQL is a lead marketing judges ready based on engagement. A PQL is a lead that’s shown buying intent by using your product, usually in a free trial or freemium tier. An SQL is a lead sales has accepted as genuinely worth pursuing. The difference is which signal earns the qualification: marketing activity, product behaviour, or sales judgement.
Marketing Qualified Lead (MQL)
An MQL has engaged enough with marketing — content, emails, events, web activity — to clear a defined bar. The signal is interest expressed through marketing channels. Its weakness is that engagement isn’t the same as intent to buy; someone can be an enthusiastic reader and a terrible prospect.
Product Qualified Lead (PQL)
A PQL has used your product in a way that signals value and readiness — hit a usage milestone, invited teammates, bumped against a plan limit. Because the signal is behaviour inside the product, PQLs tend to convert better than MQLs: doing beats reading as a predictor. PQLs only exist if you have a product-led motion where prospects can use before they buy.
Sales Qualified Lead (SQL)
An SQL is any lead — MQL or PQL — that sales has reviewed and accepted as worth active pursuit. The signal here is human judgement against agreed criteria. The SQL stage is where the handoff either holds or leaks, depending on whether marketing and sales share a definition.
Why the distinction matters
Treating all three the same is how funnels leak. A PQL nudged with a top-of-funnel nurture is being under-served; an MQL handed straight to an AE as though they were sales-ready is being over-served. Each type earns its qualification differently, so each deserves different handling.
The common mistake
Adopting “PQL” as a label while scoring it exactly like an MQL — on engagement rather than product usage. If your PQL definition doesn’t actually reference product behaviour, you don’t have PQLs; you have MQLs with a fashionable name.
Related reading
See what a sales-qualified lead is and MQL-to-SQL conversion benchmarks.
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