kenkeniff:

gnfb: 
I had some billboard type space a few years back where I lived and put up a "space to rent" sign that worked and I leased the space for $30 a month (about a meter and half square) for over a year.

Did you organise to have the billboards printed yourself or supplied by the advertiser? 

I'd imagine it would be appealing for some of the smaller businesses in the area to not have to worry about printing their own however it depends if it's worth the hassle.