Is the answer ‘good pay’? This new article examines that issue and finds that higher financial incentives alone did not significantly increase response rates. Instead:
“..this research suggests that granting bonus payments—which represent gestures of goodwill between participants and researchers—is more effective at increasing unit response, even when financial incentives are equal. ”
This is good stuff, written by Elizabeth Stoycheff, the full title is ” Please participate in Part 2: Maximizing response rates in longitudinal MTurk designs” and the full article is available from Methodological Innovations .