I do it every day, I have enough unique search terms setup to get a idea of who is getting it and who isn’t. I will say this all of them are missing a great deal and I am unsure how to explain it. I am almost positive that they really pay attention to the Top 100 or so link getters but the rest of us that are fighting for “Attention” seem to get lost in the crowd.
I find more people linking to my site through my referral logs than I do through most of these services. It is is obvious that most of them are companies that are too small to really be able to do a decent job at it all the time. Sure I love the service but they are missing stuff that’s down in the weeds.
My belief is that until the big search engines get on board this will continue to be the case. When the big search engines do get on board I feel sorry for those employed at [Technorati] [FeedBurner] [Pubsub] because if they don’t get acquired then they will see a lot of people shift to the all entailing big search engines. [Doc Searls]