SQL (Sales Qualified Lead)
An SQL is not an interesting lead. It's a lead the sales team has personally verified and decided to invest time in moving toward a deal.
“Without a written SQL definition shared between marketing and sales, every qualified lead report is just an opinion dressed up as data.”
Otto GTM ObservatoryThe line between MQL and SQL
MQL is a marketing judgment based on behavior and demographic fit. SQL is a sales judgment based on direct conversation: budget, decision-making authority, urgency, and real timeline. The MQL-to-SQL handoff is the first true human filter in the funnel.
When this boundary isn't defined with written criteria, every sales rep applies their own personal standard, making it impossible to compare funnel quality over time or across territories.
Anti-patterns
Common mistake: measuring sales team success on SQL volume generated, incentivizing reps to label any lead as qualified just to inflate the reported number.
Second mistake: not periodically reviewing SQL qualification criteria as the ICP evolves, continuing to validate leads that no longer match the customer profile generating real value.
Practical Application
Of 340 MQLs passed to sales in a quarter, only 71 are validated as SQL after the first discovery call: a 20.9% MQL-to-SQL rate. After rewriting qualification criteria with the sales team, the rate drops to 14.3% but the SQL-to-Opportunity rate rises from 31% to 58%: fewer leads, much more value per lead.