Research shows that, on average, the impact of any journal is impacted by only 15% of articles and the rest of 85% enjoys the impact without any contribution. Furthermore, many of highly cited articles usually have more than one author and interestingly it is unknown about the percentage of contribution of each of the authors.
The impact factor is increased by the increase in the number of citation. It is to be noted that the research is neither for getting more citations nor for getting famous; it is for contributing the science. Let me explain with an example. A numerical model builder gets a lot of citation as it is used by a number of researchers, but it is to be noted that the model builder is a just compiler of numerous research done by a number of researchers. However, the builder gets more citations but the real researcher gets very fewer citations. Is the number of citations really matter?