While I get the motives behind it I'm not sure it's more effective because of the overflow of information you must have on your feed. I'm a bit concerned about the signal/noise ratio in this type of configuration.
To answer with regard to effectiveness: A friend making an Indie-film used it to promote his film's trailer. He got 31 people to Ecko the trailer and in literally a few hours he crossed 700 views.
The added benefit was also that he got to see which friends generated the most amount of traffic to this trailer.
Thanks to FB's newsfeed algorithm the signal/noise ration greatly varies from person to person.