JoB-
You're being too doom and gloom: you're describing the unemployment/decreased sales feedback loop that occurs DURING a recession, but reaching a faulty conclusion about unemployment and sales overall.
Across the broad spectrum of the economy, unemployment happening out of nowhere is not the cause of a recession. Typically, some sort of shock has to occur.
Consider this case: Gasoline prices spike sharply to record levels, purchasing all over the board slows down. Less stuff sold, less stuff made, less stuff built. Companies have to downgrade their earnings reports, cut pay, cut prices, and maybe shed jobs to stay afloat.
Meanwhile, investment firms realize the mortgage-backed securities aren't worth as much as they thought (foreclosures increased due to the gas price shock and adjustable rates kicking in - and now other firms don't want to buy the securities anymore). The whole house of cards comes down in a panic plus credit freeze, and it scares the bejeezus out of everybody.
THEN what you're describing occurs.
But you CAN increase sales during increased unemployment if you can get people to stop panicking, continue buying the things they need/want, and maybe entice them with lower prices. If you've lowered your prices correctly, sales will go up based on increased volume (though with a smaller margin perhaps).
With increased volume moving, companies may need to hire more employees to manage the flow. These actions show up as "green shoots" of recovery in the media.
So the job market does DOES trail recovery.