Surf It Again, Sam

Remember that classic moment in “Casablanca,” when an angst-ridden, shot-drinking Humphrey Bogart turned to Ingrid Bergman and said, “Of all the gin joints in town, you had to walk into mine”? Well, a similar affliction seems to be plaguing Web surfers these days as a new report indicates that of the myriad sites available on the Web, many users wind up visiting properties belonging to just a handful of different companies.

According to New York-based Jupiter Media Metrix, the number of companies responsible for roughly half the time (50.4