I currently have just over 900 feeds going in to my Google Reader account, which looks to average out to nearly 400 posts per day on weekdays, and about half as many on weekends. Factor in work, eating, sleeping, and running, and it may not come as surprise that I don't get anything else done. I don't read the full content of every single article, and a handful of the feeds (and some of the more frequently updating ones) are comics. All the same, I spend a fair amount of time in Reader, and I honestly think a decent amount is worthwhile. I've said before that Reader and running were the two best things I got out of grad school.
As I added feeds, from the beginning of my time with Reader, I tried to put them in folders, and I think that's proved useful. I then have basically two aggregate folders, one ("start") for the articles and a small handful of comics, and another for some of the less-worthwhile comics (I've got an ichc habit, I'll admit it - sometimes, at the end of a long day, the laughs I get are totally worth it). I 'j' through the start items, reading headlines and maybe quickly scanning articles that catch my eye, and star the ones I'd like to actually read. After making it through the "start" items, if I've got time/energy, I buzz through the remaining comics, and then move on with my otherwise incredibly exciting life. I don't have a good feel for how long I spend in Reader in a day, but I wouldn't be surprised to find that it was around an hour. Typically I check in the morning while I'm having my coffee, and then sometime in the evening.
Recently, I found that the odd hours I wake up in the middle of the night and can't go back to sleep make some decent time to actually read some of the starred articles, but mostly that gets saved for the weekend. I love a slow morning with a mug of coffee and a few good hours reading my starred articles. Of course, some of the running I do interferes with this, but that's mostly good too.
All the same, I've been sort of trying to cut back. I buzz through my headlines and on a good week end up with maybe 20-30 items I still want to read. That's somewhere on the order of one article in one hundred. Now, maybe, for some of the articles I appreciate having the ambient awareness of having seen the headline, but I still figure there's a fair amount of cruft.
I claim to want to work on a software project that'll attempt to learn the articles I'd star, but I've been claiming that for a few years, and have yet to do anything about it. I almost made a New Year's resolution to not look at Reader, forcing myself to write my own, but that didn't happen. So, instead, I recently decided to try trimming down my feed list in Reader a bit more manually. Having quit the math and education scene, I decided to start with those two folders. Every feed in each of them is also put in my "start" feed, so what I did was remove them all from that feed, but left them in their respective folders. I let the unread count in those folders go up for a few weeks, and then read through what had accumulated to see if I'd found anything I would have missed. I moved a couple feeds into "start" and out of their respective folder (I've got a growing "misc" folder they ended up in, still a subset of "start"), and am back at 0 unread. I figure I can do this again a few more times in the next month or two, and, at some point, I just mass unsubscribe from anybody remaining in those two folders. Though I recognize optimism as the first step to disappointment, I'm optimistic this'll help me trim down my feeds.
For what it's worth (nothing), I did, indeed, manually go through each feed in my "ed" and "math" folders, clicked the little drop down for each one, and clicked to remove it from "start". Reader doesn't do much about making bulk subscription changes easy, besides being able to upload an OPML file. I actually have, in the past, downloaded my subscription list, changed the xml to accommodate some bulk changes I wanted, deleted all my feeds, and then re-uploaded my modified list. Probably would have been quicker this time too. Alas. Not my only mistake so far this year. Certainly not my last.