Ouch. If you're anything like me, around 90% of your traffic comes from mailing lists. Greplin could win big by inferring what mailing lists you are on (along with beginning and ending subscription dates) in order to factor out all relevant storage and indexing.
Sometimes it's just easier to search for things in Gmail. But since it is just a mailing list, it's pretty easy to label it and kill it en masse if you need to. At least, that's what I do.
