My main concern is - is a directory that anyone can submit to in bulk through a service without even knowing what the directory is really a directory that is going to drive value to be on? Are those really the types of directories that the kinds of people you want (e.g. paying customers vs bots) will be using? Without a list of directories and an understanding of what the 160 are, I'm frankly more worried about opening up for a lot of spam than anything - I'd rather be on 3-4 well chosen, high quality directories than try and hit as many as possible to get a big number of directories listed and end up creating more noise to sift through.
I wonder if focusing more on the quality of directories instead of the quantity could help you get more signups and users?