Another problem inherited from Bitcoin is that Ethereum is slow. It is many magnitudes slower than other platforms that host transaction data, for instance a traditional database. For example, it takes an average of 10 minutes to build a new record for Bitcoin. As a rule of thumb, after waiting for six new blocks to be built, a transaction is considered to be finalized (the same as a commitment in a database). This means that, on average, a requester will wait for one hour to see a request completed. In Ethereum, the average time for miners to build a block is 17 seconds and it is recommended you wait for 12 blocks before a transaction is confirmed. This is 12 * 17 = 204 seconds, or 3.4 minutes' waiting time for a user. Here, waiting for a few subsequent blocks to be built before confirming a transaction is useful. At any point, Ethereum can have competing chains. The waiting gives Ethereum sufficient time to work out the issue of having competing chains and reach a consensus.