Craigslist's advantage is that it's one of the most well known; not that it came up with the listings idea by itself (papers have had these ads for ages). Their

Craigslist's advantage is that it's one of the most well known; not that it came up with the listings idea by itself (papers have had these ads for ages). Their lawsuit angle was that this was a question of "method" which isn't unique. Aggregation, on the other hand, is a different matter entirely since that's essentially scraping the listings data.