This tip applies mostly to rabid online shoppers. If you're constantly copping items on Amazon, clothes off SupremeNewYork.com or gadgets from Apple.com, then it's always best to err on the side of caution by deleting stored information that probably shouldn't be on the web at any given time. What if the site was comprimised in some way? You definitely don't want your personal info up for grabs.
Delete Personal Information You Don't Want Stored