I recently sat down with Emma Weisberg of the Google Retail Team to discuss Nielsen Online’s findings on the role of the Internet in consumer research and offline purchasing. In my years doing commerce market research, what I’ve been asked most consistently about is the effect of Web site visitation on offline sales. This question is also one of the most difficult to answer. We pursued this holy grail of online research earlier this year through a combination of online surveys and our Online HomeScan panel. Watch my discussion of the results with Emma below: