Hi Jody,
Yes, you can absolutely add more than the four photos we specify for your ads. Like you said, you can actually list all 12 puppies of a huge litter right in one thread. You can create a general overall title for the thread, such as "German Shepherd Puppies For Sale." To do all this, start the thread (ad) like you would any other. Then, describe the first puppy or all the puppies, for that matter, up in the first post. Then, add four photos to that first post if you wish. Below that, continue on with adding subsequent puppies to each new post in the thread, along with four additional photos per post. You can actually grow that thread as much as you want. They are limitless.
On a similar note, if you are only advertising one dog, cat or whatever, but would like to upload more than four photos because you simply want to show the animal off as much as possible, you can add additional posts to the initial thread like I just described above. Each post gets four photos, so upload as much as you want. Enjoy!
PS - Please let me know if this answered your question.
