That is what I use with the cheap roll of plastic signs. They only last a couple years anyway. Other methods with more heavy duty signs last much longer, but for the cheap plastic signs, a cordless stapler/brad-nailer works fine. Use staples not brads. I adjust it so the staple head does not cut into the plastic sign.
We use the Ty-vec type that come in rolls. As you said, they need replacing about every 3 or 4 years. I think UV from sunlight breaks them down, and we have curious bears that seem to be attracted to anything brightly colored or that make noise when wind moves them. Claw marks tell that tale. Some break from trees flexing in the windstorms. We have to use nails with collar grommets on them - many hardwoods here, and staples or aluminum nails won't even penetrate.
Yes I probably misspoke when I said plastic. I think the roll we used with the stapler was ty-vec.
I wish our property wasn't so ROCKY. It'd be nice to be able to drive metal posts in and fasten metal signs on them, but it's impossible due to so many rocks. It's like a rock quarry under the leaf duff along the road we'd need to post. So - we're limited to posting on trees, unfortunately. I don't like using nails - but we haven't found anything else that works with hardwood trees.
Agreed, they are a short term solution to a longer-term problem.
I hired a guy with a rock drill for the 1/4 mile south fence line for the H braces they get set 4.5’ deep. I bought a rhino pneumatic post driver that did pretty well in my rocky ground. If the ground had been even worse for rock I’d of had to drill for every t-post hole but as it was I could usually move over a foot or two or three and get the t-posts in the ground.
Might be a good idea if we could find some big, flat slab-type rocks to use for signage. Not many of those around our location. Most properties in our area use either flexible metal signs nailed to trees with nails, or the Ty-vec fabric types nailed to trees. Looking at the leaves / leaf duff / moss on the ground - you'd never suspect that underneath was 4 ft. of solid rocks. Rocks run anywhere between the size of a saucer to a desktop copier/printer .......... piled tightly together. HUGE PITA for trying to drive anything into the ground.