The data seems to suggest that the large scale offering of free tickets does have a positive impact on future paid ticket sales.
However, the rest of the study may be chasing windmills:
The new study's other findings are less conclusive. Called "Assessing the Intrinsic Impacts of the Bay Area Free Night of Theater Program," the pioneer study seeks to quantify statistically such intangibles as "emotional resonance, intellectual stimulation, spiritual value, aesthetic growth and social bonding."
Some of the findings are skewed by the size of the sample - 1,409 Free Night and 675 regular ticket buyers - and its voluntary nature. As the study reports, the "self-selection" of respondents tends to generate more positive results.
Most of the less tangible results are clouded by questions of definition: Does having seen a new form of work automatically qualify as "aesthetic growth"? How does one define the elements that make up the "spiritual value" of a performance?
As I have in the past, I will let you know what I find in when I get my hands on the full study.
UPDATE: Here is the link to the full report PDF.