Business
See what people are buying with Google Checkout Trends
If you are interested in comparing the difference in popularity between products, you can use a new tool provided by Google called "Google Checkout Trends" which shows actual purchase data through Google Checkout. Although its not really a great tool for comparing items with significantly different prices, it is good for looking at similarly priced items that may compete against one another.
The reason the results aren't really valid for items that aren't priced the same is because the chart shows us the revenue of each item -- that is, price multiplied by the quantity sold. A higher price will artificially inflate "popularity".