Hi Lynn,
This may be all old information to you, but here goes...
I'm not sure how effective FeedJit will be for you since I have not used it. It is intended to appear on other people's sites and their visitors will come visit you when they see your link in that widget box. It is similar to John Reese's Blog Rush widget. My understanding is that it may bring more visitors, or it may lead your visitors away.
Best thing to do would be to test it. Depending on the number of visitors you are currently getting per week, if it's a large number the test can be for a short time, say one or two weeks. If you only have a small number of visitors per week, the test may have to be much longer. First without the widget, then with it.
You need to track how the visitors arrive and what actions they take once they arrive. There are many tracking tools including Google Analytics. Maybe someone else has tested it and can comment too.
Hope that helps!