Digimarc - Does It Really Help?

Hello! I am new to these forums so please bare with me.
I work for a company that has a very large problem keeping our images in check so to speak. As in, other companies in our field will steal our images and use them for their own. We really don't want this going on as much as it seems to be going on just because I put a lot of hard work into making our images really good, and helpful for the customer.
So my question is... is Digimarc-ing really worth it? Is it just enough to keep the wholly honest people honest?

And if so... I still don't really understand HOW it works precisely in stopping image theft. I mean, the Digimarc is invisible right? So if someone were to just copy the image, and then make a new file and such.. It would be like it was never there in the first place?

Supposedly it goes with the image even if it's name is changed, it's resized, cropped, etc. I don't know if it would still be there if the people stealing it were to do a screen dump.

Not knowing your particular business it's hard to make suggestions about other ways to protect your content but there are some things that you might consider:

- make the images small (thus undesirable).
- only let registered users view the images.
- slice the images into many small pieces. often the thief won't realize they only stole 1/64 of the total image until much later.
- use a visible watermark (thus undesirable).
- load the image(s) in a java applet or flash movie (both can make an image very hard to save if done right).

I'm sure there are other ways too, but those are off the top of my head.