My thinking exactly. I can't count the number of times I've benefited from having an old email I'd surely have thought I could delete. Things like:
* What day did I buy product X, to see if it's still under warranty?
* What was the name of that HVAC company I got a quote from three years ago, and chose not to use, but want to talk to again?
* Which room category did I book when I was last in Mexico, so I can try to get the same thing again?
All of these are things I could theoretically track down other ways, but having it at my fingertips in Gmail makes it super easy at very low cost.
Whenever I go on a particularly thorough cleaning binge I always find myself missing stuff over the next few months. (I went to Inbox Zero on my work email right before the holidays so I'll no doubt run into missing stuff over the next few weeks.)
On the other hand, the newsletters etc. etc. that I allow to accumulate in Gmail do tend to degrade search effectiveness. On still the other tentacle though, I think I'd find it very hard at this point to do any sort of meaningful culling without losing stuff I'd rather not lose.
The problem I have with archiving everything is the noise it introduces into search. That said, it's hard to know in advance what's going to be useful some day. I've never found an ideal system and I don't think there is one. I tend toward the let stuff pile up, archive selectively, and then do a broad brush stroke delete of the inbox approach.
* What day did I buy product X, to see if it's still under warranty? * What was the name of that HVAC company I got a quote from three years ago, and chose not to use, but want to talk to again? * Which room category did I book when I was last in Mexico, so I can try to get the same thing again?
All of these are things I could theoretically track down other ways, but having it at my fingertips in Gmail makes it super easy at very low cost.