The efficiency of devices dropping on commerce channels reduces as the total value of the money transfer events cracked by a player increases. If you have recently cracked a high value event or several low value events, then your devices will be less effective at detecting money transfer signals.
The efficiency of a device that is dropping varies between 100% (normal efficiency) and 0% (no signals will be detected). Dropping efficiency is calculated as follows:
For each money transfer event that has been cracked in the past 24 hours, multiply the amount received from the crack by the percentage shown on the following graph to produce a "weighted crack amount". Sum all of the weighted crack amounts to calculate a "total weighted crack amount". You will see that the most recent cracks contribute most to the total weighted crack amount. The longer ago the event was cracked, the less it contributes to this total. But also the less the value of the crack amount, the less it contributes to the total.

For example a 500,000 money transfer event that you cracked 12 hours ago will contribute 250,000 to your total weighted crack amount. A 1,000,000 money transfer event that you cracked 20 hours ago will contribute 167,000 to your total weighted crack amount. If these two events were the only ones you had cracked in the past 24 hours, then your total weighted crack amount would be 250,000 + 167,000 = 417,000.
Once the total weighted crack amount has been calculated, the dropping efficiency is calculated as follows. If the total weighted crack amount is over 1,500,000 then the dropping efficiency is 0%. If the total weighted crack amount is zero, then the dropping efficiency is 100%. For total weighted crack amounts between zero and 1,500,000, the dropping efficiency is a straight line calculation between 0% and 100%

For the example above where the total weighted crack amount was 417,000, the dropping efficiency for that player on commerce channels would be 72%.