Pull may be more efficient for distributing a great variety of information to recipients with different needs. The computer industry has concentrated far more on push than on pull, perhaps because the the Web constitutes a remarkably effective pull mechanism on its own when security isn't a big concern. Several push systems are commercially available to ease the distribution task for both providers and recipients. Such systems are not necessarily interoperable, however. They consume somewhat less network bandwidth, but there's still no easy, broad-brush solution.
Timing can be critically important in selecting a distribution mechanism.
Availability is another consideration. Bulky video or large multimedia graphics broadcasts can bring almost any network to its knees. Compression, though helpful, is far from a panacea. Most push products include technology to trim bandwidth requirements. Location matters, too.