The three most impactful parameters for understanding a consumer along her journey are:

Recency: has the consumer expressed interest in a recent period?

Frequency: how often has the consumer expressed interest?

Engagement: how deep is the consumer's research?

Once you have a view of these three parameters, you can place every consumer in the appropriate stage of their buying journey-be it the attention (general awareness), interest (researching broad options), decision (narrowing options), or action (taking the action to purchase) stage.