General discussion of Anglo-Saxon coinage tends to deal much more often with the hoards than the single finds. Hoards are certainly more dramatic, and it is easier or more tempting to try to link them up with large historical events. A hoard may indeed be deposited in response to external pressures (such as Viking invasions), and only survive to our day if the original owner is prevented from recovering it later. But to extrapolate more general trends of coin circulation from the pattern of hoards, it would be necessary to have a complete knowledge of the historical factors that led to the deposition of hoards, and then to perform some complicated discounting to explain the hoards that were probably deposited, on the historical model, but were later recovered and so have left no trace. In other words, it can't be done.
This is where the evidence of the single finds comes into its own. Individual coin finds are much more likely to be accidental losses than deliberate deposits. This is seen most clearly in the many 'productive sites' (sites which have produced a large number of single finds) which are known from other sources to have been markets in the middle ages, where one might expect more frequent accidental coin loss. Not all single finds need be accidental losses; before 600 AD, for instance, coins are much more likely to be deliberately deposited grave goods than accidental losses. But in the main, it seems reasonable to assume that the pattern of single finds is representative of the coin circulating in a given area at a given time.
The Anglo-Saxon coin finds of Cambridgeshire demonstrate the differences between hoard and single-find evidence. There are only two clear hoards of the period from Cambridgeshire, one from the eighth century and one from the end of Cnut's reign (c. 1035; perhaps laid down because of political uncertainties in the reigns of Harthacnut and Harold Harefoot). There are four more groups of two or three coins which might or might not be deliberately deposited hoards (one from the eighth century and three from the tenth). In contrast, there are over fifty sites in Cambridgeshire with recorded single finds, and these cover a much larger area and include coins from periods in which no hoards were deposited and for which we would otherwise have no evidence of Cambridgeshire circulation. The hoards and the circumstances of their deposition are flashes of lightning by which we can read (or guess at) momentous events, but the single finds illuminate much more clearly the day-to-day picture of coin use.
A detailed knowledge of coin circulation contributes most obviously to wider historical knowledge in the seventh century and the first half of the eighth, the period of gold shillings and early silver pennies ('thrymsas' and 'sceattas'). Most of these coins are anonymous, with no indication of where or by whom they are minted, and the distribution pattern of finds is often the only evidence for locating them. Sometimes the patterns are fairly conclusive. One series of early pennies, series R, is found almost exclusively in the old East Anglian kingdom, and was presumably an East Anglian coinage; another, series H, is found in vast quantities in Southampton (Hamwic to the Anglo-Saxons), but rarely anywhere else. These are clear-cut examples, but there are others where we are much less certain where the coins were minted or where they circulated, and new finds from unexpected findspots can change previously suggested attributions.
The complete corpus of single finds will become an essential tool to help answer many other questions of economic history, and the fact that the corpus will be kept up-to-date will mean that the findings of earlier studies can be checked against the latest information.