Fees are tied to the volume of data that needs to be transferred. As a result, some transactions are delayed, waiting for confirmation. Using these online estimation services, you can also convert satoshi into USD or other popular fiat currencies. Our service will rebroadcast the transaction via 10 Bitcoin nodes. When the network is congested you can actually use a Bitcoin transaction accelerator. Since each block in the chain can include a limited number of transactions, your fee has to outbid other users for your transaction to make it in the block. When more people start to use Bitcoin, the block size reaches the limit and leads to crowded Bitcoin network.