The reason this shouldn't be implemented in the United States is because it's a two-party system at every level of government. And then there are independents who vote one way or the other depending on the candidate. It is a good idea, but would not work in the United States.
I think that it would save time, money and problems if the voting process was instant. Some of the problems are the long lines and somewhat early closing. When a place can stay open longer because it wouldn't have to count the results. A place that's open longer has a better chance of getting a higher turn out of people.
Instant run-off procedures in American voting would save time, money and effort if people simply choose their top three candidates in order of preference. If one person gets more than 50 percent of the vote, that person wins. If someone doesn't get a majority, the second and third ballot choices are counted until there is a clear winner. This method saves loads of time, simplifies the voting process and innovates voting procedures in the United States.
In the United States there are generally only two serious candidates for an open position with the third parties gaining a very small slice of the vote so I don't really see a benefit for the United States to have run off voting in this current environment, either one side wins or the other side wins.
No, instant run-off voting should not be instituted in the United States' electoral process, because it would be very expensive. Most of the time, the same candidate would win anyways, so there is no purpose to resigning the voters to the extra expense of having additional elections. The electoral college works and it is our tradition.