In September I was helping a client comp out a new landing page after they had lost their in-house dev. The product's photography wasn't done and that meant using placeholders.
There are pretty much two options when placeholding photography; you can go pick stock photos or you can block out placeholders with gray boxes. The problem for me is that stock photo selection is unnecessarily time-consuming, and gray box placeholders are ugly. So I poked around for a paceholder.com alternative that used real photos.
What I found was pretty much just other gray box services and a couple that serves cats. No service that just serves relevant placeholders.
So I built https://imgy.dev
It's not complicated, it's not exciting, and it won't shatter any records for uniqueness. It's exactly like the rest of the tools I build; it's simple, easy to use, and accomplishes its goal perfectly.
That is the secret to success when you are bootstrapping your own SaaS (or ecom or agency or whatever). You find a specific thing and target it exclusively. And that's harder than it sounds.
It's so tempting, especially when you report to no one and you're doing your own thing, to give in to the never-ending parade of ideas you have or features you could implement. The secret to overcoming is the same for a solo founder as it is for an agency with a client; scope.
If you're out there building a new thing or are about to, define it. As narrowly as possible define it, who will use it / buy it, and how you're going to reach them. And then build & deliver that.
It won't be everything it needs to be, it won't reach everyone you want it to. What it will do is give you momentum, a platform to grow on, and (not to be underestimated) the sense of accomplishment from setting a goal and achieving it.
That's it. That's the secret. Pick, narrow, launch. It's harder than it sounds.