The number of great successes that allowed software developers to retire in luxury based on donationware/shareware was pretty small. But it often worked well enough for a lone hobbyist who wanted to cheaply distribute a program, and make enough off of it to support his computing hobby.
One success was PKZip. It was shareware, and it was so useful that almost everyone had it. I don't know what percentage of people paid for it, but it was enough to make PKWare a success. Sadly, Phil Katz, the programmer whose initials were incorporated into PKZip's name, died in 2000 at age 37, due to effects of chronic alcoholism.
There's still a fair amount of software that is distributed for free, asking for donations to license it. Sometimes a paid license enables extra features, or at least disables a "nag screen".
But with today's ubiquitous Internet connectivity, you don't often find software that contains a plea to "Please make copies and share them with all your friends". We forget how hard it was to distribute software without any Internet infrastructure. Dial-up BBS systems were slow, and not so well connected to one another. Getting something from a BBS in another state at 300 baud would often mean a very expensive long-distance phone call. Today, the software author just puts the latest copy of the software up on a website, and lets everyone grab it from that one spot.