I figured out why reporters tweet so much.

Figured it out while reading another generous handful of tweets from Ana Marie Cox. In reverse chronological order:

Thank God Nico is so tall. He let me stand in front of him. Fuck you line cop. #whp
about 4 hours ago from Tweetie

HuffPo's Nico Pitny just placed in 2nd row of SRO by WH staff. Now why could that be? (Nice "fuck you" to guy next to me playing line cop)
about 4 hours ago from Tweetie

.@jaketapper says photogs "formally request" no rising in their way when O enters. And those of us standing might try to take their seats.
about 5 hours ago from Tweetie

And my view if I turn around... @mikememoli says hi. #whp http://twitpic.com/872ib
about 5 hours ago from Tweetie

RT @newmediajim @anamariecox prodded me into taking updated POTUS view. Crowd has grown! http://twitpic.com/8719t // #1stcome1stservefail
about 5 hours ago from Tweetie

My view. http://twitpic.com/871bj
about 5 hours ago from Tweetie

.@newmediajim standing in for POTUS. The resemblence is remarkable, no? http://twitpic.com/870pq
about 5 hours ago from Tweetie

Actually I have just elbowed my way to the front. I am refusing to believe you can "save" a space on the wall. #whp
about 5 hours ago from Tweetie

Sitting in an edge seat that I know will be taken has benefit of putting me in place to have a good place to stand... #whpresser #whp
about 5 hours ago from Tweetie

Hey that red blob in the middle is me standing up! RT @newmediajim: POTUSeye view of the White House briefing room http://twitpic.com/86xmg
about 6 hours ago from TweetDeck

They are so often stuck in waiting situations.

AND: Related question: Why do law professors blog so much? Ha ha.