I have some photos on flickr getty. I havent made a lot of money yet. I was invited much like you have been. They asked for some 70 photos and I have about 30 on getty. My experiences are as follows:
1. The curators pick photos that are sell-able as stock. They are not necessarily very artistic. I would think that you have to shoot with that in mind if you want to make good money.
2. The commission that getty charges is pretty steep, so get into the program only if you have no other ways to market your work.
3. Only enter those photos into getty that you dont mind being sold as stock. If there are photos that you have that you think that can be monetized otherwise such as through independent sales or by publication as a book etc. then keep it with you.
3. Getty does not own the photos, the copyright remains with you. It only has the right to license it for use by other users. You can cancel this permission at the end of the contract, or choose to continue it. As has been mentioned above, you can continue to use those photos for self-promotion or even as prints.
4. I entered this program because it seemed like fun, I do not have the ways and means to market my photos independently and a little extra money is always welcome.
5. Being successful on Getty is a combination of luck and having a collection of good, sell-able, stock photos.
Best of luck.