Ask HN: Is it viable to start of with ads for a listing site

I am trying out a small experiment. Adding features to classifieds, and taking care of several things. The revenue model that every other listing site does is

1. Paid Listing

2. Ads.

The doubt I had was, do folks at HN think is it a good idea to start of with Ads as the primary revenue stream.

If people can throw in some pointers around what else would be a good approach, it will be helpful for me to think about it.

Thanks!