  Promotions are commonly used by e-commerce merchants to boost sales. The
efficacy of different promotion strategies can help sellers adapt their
offering to customer demand in order to survive and thrive. Current approaches
to designing promotion strategies are either based on econometrics, which may
not scale to large amounts of sales data, or are spontaneous and provide little
explanation of sales volume. Moreover, accurately measuring the effects of
promotion designs and making bootstrappable adjustments accordingly remains a
challenge due to the incompleteness and complexity of the information
describing promotion strategies and their market environments. We present
PromotionLens, a visual analytics system for exploring, comparing, and modeling
the impact of various promotion strategies. Our approach combines
representative multivariant time-series forecasting models and well-designed
visualizations to demonstrate and explain the impact of sales and promotional
factors, and to support "what-if" analysis of promotions. Two case studies,
expert feedback, and a qualitative user study demonstrate the efficacy of
PromotionLens.
