The paper is a survey of repeated surveys with a few examples. Repeated surveys are surveys conducted across time. Therefore, the results appear as time series. The main question in repeated surveys is how to summarize the results, either using only the last survey or using some (weighted) average of the most recent surveys. An example in economic statistics will be treated: the monthly business surveys in several countries. Besides, simulation results are presented based on some of the techniques proposed in the literature on repeated surveys and TRAMO-SEATS sometimes used for business surveys.