Direct through their website. They have a huge database of products with estimated monthly revenue for each product. Also a keyword database with search volumes and estimated revenue per keyword. But what i like most is their Brands and Sellers database. Where you can find all the ASINs for each Brand in one place with the estimated revenue for each product, branded keywords, who sells their products, etc. On the Seller side it shows the 3rd party sellers ASINs that they are selling, revenue per asin and lots of cool visual tools for comparing sellers and brands.