There is something really interesting going on out there in Waterloo, Ontario, where AideRSS today announced a major new service called PostRank.com, which enables users to see the most popular content based on various social engagement metrics. It is available as an API which website publishers can incorporate in their sites. AideRSS’ product offering uptil now was focused on filtering the posts in a RSS feed based on popularity – how many comments, diggs, etc a post got. In the past, users could go on their site (www.aiderss.com) and filter their RSS feeds or install an extension for Google Reader and some other feed readers to sort the posts by their “PostRank”. That was quite interesting itself, but now they have opened up PostRank beyond RSS feeds, and for regular blog posts, news articles, bookmarks, etc. Any kind of online content! This is where it gets really interesting and opens up a much bigger market opportunity for them. This is something which the likes of Google will eventually have to co-opt or compete against. The main challenge for AideRSS in the short term though is going to be driving the adoption of PostRank across the web and convincing the rank and file web publishers to adopt it. Besides this new PostRank service, AideRSS also announced the official launch of their Google Reader extension and updated APIs. In my opinion, this is THE Canadian web startup to watch out for.