It's a combination of frequency-of-use and pain-of-problem. You use Zillow infrequently, but when you do use Zillow, you're like, "Holy shit guys, this is my h

It's a combination of frequency-of-use and pain-of-problem. You use Zillow infrequently, but when you do use Zillow, you're like, "Holy shit guys, this is my house! It costs hundreds of thousands of dollars and I have to live in it for years!" You're more incented to seek out really good tools. The problem with infrequently used sites comes when the pain point is fairly small. Even if that pain is reduced a LOT by the site, down to almost nothing, if the absolute magnitude of the pain of the problem is low enough, it's just not worth it for people to hunt down their vague memories of a site and try it out and see if it's any good and learn its process. They'd rather accept the pain.