Here is what you can do...
You will need one Craigslist account on a unique IP address for every 25 posts per day. You will also need one unique phone number or landline forwarded to a phone for each account. (You can Google "PVAs" and "forwarded landlines" to purchase these things.) Then, you can use an auto poster to rapidly post tons of listings and home lists, which link back to an IDX site with an opt-in form.
This allows us to post 100+ ads a day, and capture at least 25 leads a day.