Tracking services or audits have been the staple of a number of marketing research companies, such as IQVIA with its pharmaceutical sales tracking audits and Nielsen with its fast-moving consumer goods' (FMCG) audits. Such audit services provide a regular read of a defined market, supporting marketing decisions by client companies. Clients rely on such services to provide insights informing business decisions, such as whether to enter a new market (through marketing sizing and competitive analysis) through to measuring their performance inside a market against their competitors. More granular services can provide information, such as inside sales territories allowing client companies to size the market accessible to their individual sales representatives, target their sales activities better, measure their performance against competitors and against the market available inside a territory, decide the boundaries of sales territories, and finally use the data as the basis of incentive programs for the sales staff. Quality is of utmost importance to such services, increasingly so as the granularity of the service increases in both geography and time, leading audit companies to vigorously explore data sources to expand coverage and accuracy.