I like the fact you mentioned that the post are searchable in google... I did not actual even realize that! To add to the picture/facebook comment from @ginacarole there is absolutely no stopping anybody to do exactly what they do on facebook.... the best for new users without much SP and any proper input to the platform is just to do exactly what they do on FB.... bring your friends that are already liking your pics on facebook and create your own audience.... plus if they all decide to invest few hundred bucks and turn them into SP then there you can have a nice closed circle community... Well, just my thoughts!