ISO Offline Advertising Ideas for Website

Does anyone have any experience with offline advertising to drive traffic to a website with a positive ROI?

I have a decent size budget for advertising, and looking for advice as to where to spend it.

Industry: real estate
Audience: Local

I have considered either billboards or TV.

Any suggestions as to what offline medium works and how to create the ad content so it will drive traffic?

local press is normally great for real estate, people scan it at the weekends

Co-op saturation mailing...find 3-4 service businesses to share the cost with and increase the retention of the mailer.

Letterbox drop-offs in my experience fail epically.
Really depends on the site itself and what it does EXACTLY, but if you approach real estate companies in your area, given you have good traffic to your site, you might be able to squeeze them enough to have a banner ad for them on your site for a monthly charge in the 3 digits. You could do that to a few local real estates before they start to get annoyed at you for conflicting ads. Throw a bunch of investor talk about expected turnaround and cost of marketing research in their face to convince them it's a good idea. It'd be better than adsense if you have that going. You could get $1200 a month or so out of it if your site it apt.