Why it matters
Beware the single loggers. One big session is a false signal.
Here's the lesson that's worth the whole page. At PipelineCRM we ran a two-week trial. Some prospects closed themselves — upgraded and bought without a conversation — but most needed a salesperson to close, and our reps automatically reached out to trial users to do it. The signal that told them who to chase was usage: heavy trial activity, and especially adding additional users, reliably predicted who would buy. Reps looked at account usage to prioritize who to call. That's a PQL motion, whether or not we ever used the term.
But raw usage fooled us until we learned to read it right. We had a whole category of trial users we called "single loggers" — they'd sign up, do a decent amount of usage in one sitting, and then never log in a second time. On a naive usage score, a single logger can look like a hot lead: lots of activity! In reality they were nearly worthless, because the activity was one burst of curiosity, not a pattern of value. The fix is to measure usage over many days, not in total. A prospect who comes back on day two, day four, day six is forming a habit. A single logger who never returns is just tire-kicking. Sustained beats intense, every time.
That's the real PQL principle, and it lines up with everything else about engagement: the buying signal isn't "did they do a lot once" — it's "are they building the product into how they work." Multi-day return, expanding to more users, getting deeper into the core — those are the signals that a trial is becoming a customer. Get the definition right and your sales team stops cold-calling and starts calling people who are already half-sold. Get it wrong — count single loggers as leads — and you'll waste your reps' time on prospects who were never coming back.