This is a common analysis situation which I've come across, but it makes me feel a little uneasy. Its finding the correlation of 2 variables after they have been aggregated. I haven't got any concrete numbers (they're commercially sensitive), but here are 2 examples:
In a call centre we have speed to answering the phone (variable A) for the past 12 months (n=12) and customer satisfaction (variable B), again for the past 12 months. What does the correlation between the 2 variables aggregated by month tell us? If it was a strong negative correlation, say -0.9, does it mean that slow answers lower customer satisfaction
Suppose a company ran a staff satisfaction survey on its 30 departments (n=30). It measured the staff turnover (variable A) and staff satisfaction aggregated for the department (variable B). What does the correlation between the 2 variables mean?