Low technology billboards

People driving down Mumbai roads (especially the one next to Mahalakshmi race course towards Haji Ali) would have seen people standing on the sides with small posters/ placards.

My theory was that foreign marketer's would miss this kind of low-cost advertising opportunity. I was wrong as these low-technology billboards show. Now, I want to see cows doing the same in India. Is Airtel listening? Will we get over this?