Three particular issues particularly manifest the cliff effect. Firstly, anomalous conditions will cause occasional signal degradation. Secondly, if one is located in a fringe area, where the antenna is just barely strong enough to receive the signal, then usual variation in signal quality will cause relatively frequent signal degradation, and a very small change in overall signal quality can have a dramatic impact on the frequency of signal degradation – one incident per hour (not significantly affecting watchability) versus problems every few seconds or continuous problems. Thirdly, in some cases, where the signal is beyond the cliff (in unwatchable territory), viewers who were once able to receive a degraded signal from analog stations will find after digital transition that there is no available signal in rural, fringe or mountainous regions.