[creativename]

I'm sure this has been answered before, but why does it matter to Craigslist if it's data is being used elsewhere and is clearly marked as Craigslist data?

Say Craigslist is paid for real estate listings: they already have the money, and they don't make any additional money off of advertising, so why does it matter where someone accesses that information?

I'm genuinely curious why this isn't similar to Twitter, for instance, allowing developers to show tweets in their own applications. Except in this case, people are paying to "tweet" (post real estate listings). Also, for this question, I'm ignoring Twitter's recent policy changes.

I suspect I'm being naive here, and the issue may be that they just really don't want other people profiting from their data, but I guess I just don't get it.

[jaredsohn]

The problem is that if another site has the same listings as Craigslist and provides a better user experience, people looking to rent an apartment will start visiting that site instead of Craigslist. Over time, people looking to list apartments that want an audience of renters would start listing on that site directly instead of Craigslist, since that is now the best place to find renters.

[creativename]

Ah, so in that case it would literally come down to not wanting to have to innovate. If they truly thought that people preferred to have it the way it is, you'd think that they wouldn't be afraid of this.