OK, Redfin has my attention. In the old days (you know…yesterday), a home search that covered too broad a price range or home style or area would result in an annoying message about how Redfin could only map 500 properties at one time.

Now the site lumps homes into clusters; those clusters grow and cover more ground as you zoom out, or split apart and cover small sub-neighborhoods and mini-markets as you zoom in; it’s only after you’ve narrowed your criteria or zoomed in very closely that you see individual listings pinpointed on the screen. Hover over any cluster, and you get a breakdown of the types of homes for sale, their price range, and an average price. If you use Safari or Chrome, you get some fun animations with all this, to boot.

According to Redfin’s corporate blog, the site “dynamically sizes and locates the clusters based on a real-time survey of listings in the area. As a result, we never show an out-of-date view of the listings in an area,” but it’s still not clear how Redfin decides where one cluster ends and another begins. (What sets that 186-home cluster highlighted above from the cluster of 82 immediately south?) Because of that, I don’t know how much value they have as market snapshots, but I’m willing to play around with them and find out.