Some people, apparently erroneously, said that Twitter is testing ads mid-stream just like clients such as Twitterific do.
I didn’t think this was new, as when I look at my stream I see something like that image above. Isn’t it already ads? :)
Twitter is the watering hole for those of us who don’t work at the same company, and we are Beacon’ing all the time.
NOTE: This isn’t a bad thing at all. And, I know that I do it all the time!