[richardv]

Is this even possible?

1000 listings, and 50 dollars invested, would mean that even at a 10% conversion rating which I think is safe to say, for a fresh launched website is obscenely high, would mean you were paying 0.5 cents per click. (half a cent).

I don't think your advice is applicable to what the original posters wants.

Without knowing what exactly the OPs business is....

It's a poorly phrased question, 1000 (paying?) users, and retain them for what duration? Are you just wanting 1000 MAU, or just views... With 1000 users, depending on your signup, this could mean a factor of 1:20 of users to views. Both of which could be irrelevant to your actual businesses main metric which is sales?

To the original poster, try and clarify what you are asking...

[meerita]

No, I told the poster to try AdWords, to see if the product has some, gain. Our history was different and, we go a lot of listings because: our product doesn't requiere registration and its really easy to publish, and there were people posting and reposting the same ads on different states so that's why we got a lot of traction the first day. The problem? next day the ratio of people was null, and so on but we got indexed and without spending another dime we're growing. It's a nice experiment we did, we're not interested on the listing business.