When to check for confirmationsl When monitoring incoming transactions for a web wallet, should I check for confirmations on a timer, e.g. every minute? Or should I check once every block by using blocknotify?
This is a nice chart on the average transaction confirmation time: https://blockchain.info/charts/avg-confirmation-time that will give you a better estimation on how often you should check. 

Also related: What keeps the average block time at 10 minutes?