That wasn't "lock in" it was an opportunity, they sold these folks on lower costs (since Classifieds were a money fund for newspapers) Landlords hated the extortionate prices that the newspapers charged but they didn't have an alternative, Craigslist gave them that alternative, they moved.
But you are using an example in which there was a clear downside to using the existing listing model. The price. If you are a landlord and you have no problem renting out apartments in a reasonable amount of time on Craigslist, and it's free, what exactly can another site offer that is "better"?
They are already getting their apartments rented, there is minimal overhead to using Craigslist. You can't compete with Craigslist on price, unless you are actually giving landlords money for listing on your site. And trying to say "It's easier for users to find your properties." doesn't help if they aren't having a problem with renting out their properties.
But you are using an example in which there was a clear downside to using the existing listing model. The price. If you are a landlord and you have no problem renting out apartments in a reasonable amount of time on Craigslist, and it's free, what exactly can another site offer that is "better"?
They are already getting their apartments rented, there is minimal overhead to using Craigslist. You can't compete with Craigslist on price, unless you are actually giving landlords money for listing on your site. And trying to say "It's easier for users to find your properties." doesn't help if they aren't having a problem with renting out their properties.