I would say a 4 to 5% result rate was on the high side for this kind of advertising, I would think its more 1 to 2%.
Its a lot of hard work for such a small return rate. You would possible do better by trying to get your service inside the official program guide, people tend to sit and read those at home as they also contain other related products/services.
There is also nothing worse for business than seeing your advertising on the ground trodden on when some people drop or throw them when out of your site.
