Which reminds me:
Although I haven't yet put full faith in the data, being able to see Price, Stock, & Popularity (not really sure what is) along a history graph going back a year or three is - excuse my Australian - effing brilliantly useful.
Several times now I've narrowed down a search to 1 of a few chips, and then its just, for example, chip package options to select from. Maybe I'd prefer the MSOP8, but that's been out of stock for the last 6 months, so SO8 it will be.
At the very least that's the best time to be provoked to go check availability on a few retailers sites just to be sure, and more often than not parts.io has been correct.