Offering incentives

Basically, incentives ensure that miners continue working for the network responsibly (in other words, consensually validate correct transactions). The work provided by the miners is rewarded by the cryptocurrency underlying the blockchain. By implementing rewards, people are encouraged to join the community and become miners, who, as a result, contribute to broadening the network. And the more miners there are, the larger the network and the more secured are the transactions because the less chance there is for the blockchain to be controlled by one party or individual.

Note that the rewards are usually decreasing exponentially over time because a blockchain often starts with few miners before enjoying a network effect and attracting more miners. Joining a blockchain early as a miner ensures you to gain more cryptocurrency even though it is not worth much at the beginning. But as more miners are joining the network and as more users are using the service, the cryptocurrency itself starts gaining consideration, hence, value. In this manner, rewards for miners usually decline over time following a predefined algorithm as more members join the network. For Bitcoin, for example, the original block reward was 50 Bitcoin, planned to halve every 210,000 blocks. As of June 2019, the block rewards are 12.5 BTC and total supply is set to 21 million BTC, the last unit of which should be allocated in 2140. What is important to remember as a decision-maker is that incentivization is an important component of a blockchain because it answers the following question: what are the interests for a miner to continue to validate the transactions happening in the network? Put differently, what is the motivation of the validators to keep ensuring the truth within the registry?