For whatever reasons, there is value associated with a signature on any artwork.
Whether you are "somebody" or not, potential buyers of your photographs perceive that there is a higher value with a real signature. They don't know if you are "somebody" or not, so just in case you might be, they will be more likely to pull out their wallets for your print over the one next to it without a signature. This, of course will increase the possibility that your prints will sell and isn't that what you really want?
Secondly, as you sell more prints and more people see them and word of mouth spreads, people will go looking for prints that can be verified to be your originals by your signature so after awhile you will start to become "somebody" and eventually when you ARE "somebody" those little prints will be worth a lot more than what they originally paid for them.
Then you can make bigger prints with your signature and sell them for a lot more than you can today and retire a rich "somebody" in high demand and I can claim I once gave a very famous "somebody" strategic advice when they were first starting out and get my picture in People Magazine!