In the previous example, once the event was produced and retrieved by the downstream systems, an additional operation needed to be executed in order to obtain the details associated with the transaction. This determined what action needed have to been performed as part of the process. This additional operation involved establishing a communication with the source application. This step could take only a few milliseconds in some cases, but the response time could take longer depending on the network traffic and latency. This would then influence the performance of the dependent systems. 

As a result, the size of the payload provided by the source application increases, but less traffic is required.