They have a mechanism so the DAG is single ended, which means if 10,000 senders make a payment they will verify each other and there is only one at the end. This is a high volume transaction tech used on IoT, which means there is a huge amount of transactions per second. Your payment will usually get verified in milliseconds while on blockchain it takes 3-5 seconds. If a machine plugged into the network is appending his sensor data to the network there is a continuous stream of transactions so the scenario where there is a very long time world wide without a transaction if very much unexpected.