[bduerst]

People who purchase something online are magnitudes more likely to purchase it again than someone who hasn't made the purchase.

[oneeyedpigeon]

Surely it depends on the product - e.g. USB stick versus engagement ring.

[bduerst]

I doubt there is a huge market for online engagement rings, coffins, or other once/twice a lifetime purchases.

For gifting espresso grinders, it's not unlikely that purchasers will buy it as a gift again for their parents, friends, etc.