Crash course on the Importer?

[ninetydegrees]

Dear people with knowledge, could we have more detailed answers about how the importer works *exactly*? Like how many times a job tries before it gives up (5?), if a job goes to the bottom of the queue every time it fails and other things I'm not thinking of? These details won't necessarily make it into support answers but I feel it would help me to have this background knowledge.