I had an interesting conversation recently via email with a marketer who is using RSS. He's using Web beacons -- tiny 1x1-pixel images also used by email marketers -- to count the number of times a message is viewed, but he's running into two common problems. One is that Web portal feed readers such as Yahoo! and AOL don't support images in RSS feeds. The other is that some RSS readers that do support and display images in feeds, cache the images, making tracking impossible beyond the first view.
He asked if I knew of any solutions for improving RSS measurement. The fact is, first-generation RSS faces the same challenge today as first-generation Web and site analytics did in the late 1990s -- it relies on incoming page requests and attempts to decipher IP address and other indirect information. I believe these methods are reasonably accurate, but they are nowhere near 100-percent accurate.
I advised him to take a look at the emerging new generation of RSS feed systems based on Individualized RSS. Companies like Silverpop, SimpleFeed and Syndicate IQ already have commercial IRSS applications that are worth taking a look at. IRSS works by creating a unique feed for each subscriber (rather than a single feed for all subscribers). With IRSS, pixel tags are individually-named, so they don't get cached. And, even if a feed reader doesn't support images, you can still infer a great deal about behavior because you are able to measure individual click-throughs, which gives you real insight into how subscribers are responding.
For marketers who want to stick with the current RSS technology, companies like FeedBurner and others have invested huge effort into maximizing the measurability of traditional RSS. Since their services are free, you really can't go wrong using them.
But in my opinion, marketers need far more information than they can get with RSS. I believe this will drive an inexorable move toward IRSS over the next five years. Since the consumer experience is identical, it's only a matter of marketers getting their heads around the technology and the slightly higher costs.