I've wondered for a while about some hybrid push/pull distribution scheme. I have 100 followers, just push. Oprah has 1M, 1% of which are currently active, pull. Sounds complicated, but feasible.
But is also has to do with how frequently the information is changed/accessed.
e.g. If Oprah only publishes 3 tweets a day, but her one million followers each check 100 times a day (just to be on the bleeding edge of gossip), it's much less effort to push the change.
On the flip side, if you post status changes several times a day but your followers rarely check (daily/weekly), pull may make more sense.
Although, I suppose that a push inherently requires an update/write, while a pull is generally a read. Seems like this might need to be taken into consideration as well.
