A method of singulating and feeding a random mix of thick and thin flat articles includes: (a) sensing whether a flat article is positioned on a feed conveyor in a position for removal from the feeder conveyor with a sensor, (b) advancing the feed conveyor with a first motor an incremental step to place a series of flat articles positioned on edge in a position for removal from the feed conveyor each time the sensor detects the absence of a flat article for removal from the feed conveyor, (c) counting each incremental advance of the feed conveyor, (d) incrementally advancing the stack of flat articles with a jogger driven by a second motor after the feed conveyor has moved a predetermined number of incremental steps to load additional flat articles on the feed conveyor, the jogger tending to edge the flat articles for removal from the feed conveyor; and (e) repeating steps (a)-(d) while sequentially removing flat articles from the feed conveyor on a one-by-one basis as the feed conveyor is advanced. The method is implemented with a feeder comprising a belt type feeder conveyor, a chain driven, finger type jogger and a belt type entry conveyor where the flat articles and/or mail pieces are loaded edgewise.