Don't give up. We have several large, old albums (about 95 % of the images are unlabeled and of the few that do have something written on the back the wording is unhelpful ('mother,' 'father,' 'you'll know who this is,' etc.).
In pre-internet days I was able to contact a distant connection related to my husband's mother. I took all the photos we have belonging to her family as well as any that were taken in the place we know some of the family had lived and any that even seemed to show a family resemblance then photocopied all of the photos. After numbering them I sent this relative copies. He was then able to identify a good portion of the unknown ones with comments like 'grandfather & family,' 'grandfather's parents' and even 'don't known who they are either but we have the same picture.'