You can think of proof-of-work as a competition to approve transactions. Each entry in the competition costs a little bit of computing power. A miner’s chance of winning the competition is equal to the proportion of the total computing power that they control. So, for instance, if a miner controls one percent of the computing power being used to validate Bitcoin transactions, then they have roughly a one percent chance of winning the competition. For instance, what does it mean to say “once enough people have broadcast that message”?
With more than 4 million users, Bitso calls itself the most popular and largest platform of its kind in Latin America. Yet globally, CoinMarketCap ranked Bitso in 67th place on its list of top https://bitcoinczechia.com/ exchanges at the time this story was published, reflecting the limited scope of the deal. But consider that a significant amount of bitcoin is also being held by investors. Those investors do not plan to sell their bitcoin for some time because they are speculating that due to its utility as MoIP, demand will continue to rise and so too will its value.
Who is going to be looking to reject it, and what does that even mean? If a malicious party manages to complete a block that contains transactions that are not, in fact, valid then what? Do other miners check them before building on top of her faulty block? And, if not, then what does it mean for others to ‘spot’ them.