Reduced by 19.92 MB and you're ecstatic, or by 19.92 KB and you're being ironic...? On the default setting of 10, I reduced a 1665 KB Poser .tif to a 81 KB .jpg. A 184 KB .jpg went to 65KB. A lot depends on the software. Those results are pretty typical for Poser .jpg files saved at 100. If you're already using PhotoShop's optimization you'll probably get less of a reduction.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken