Who do you use for the ads?
I use Ad network. I can't post the link here. It contains affiliate code. Not allowed.
PM me if you need the link.
Don't nurse the wrong impression that you can seriously monetize one, undeveloped domain, without content. See below for screenshot for 1 month earnings /10 domains (including a niche blog with few articles). Just about $4. It could have been more than doubled, with video ads.
So, you should be thinking of tens, hundreds, thousands domains - if you want handsome income.
And not all domains/websites can be monetized with ads. Traffic is paramount. So, here are the steps to follow:
1. Register with the ad network. You must indicate your domain portfolio website, will your domains redirecting to the site.
2. Wait a couple of days for review and approval.
3. Select the type of Ads you'll like to display on the domains ( banners, video, text etc. There're 15 types in all.).
4. Get the code(s) and insert on the header/footer part of your website and/or domain landing pages. You insert the codes once. You can still have offer/BIN form on the domains if you're selling them.
The standard banner ads are not intrusive and you still retain your brand identity. Video ads fetch more, but can be intrusive.
how do you work on driving traffic to those?
You can drive traffic to the domains/portfolio by using the same network to advertise with part of your earnings. You can also become an affiliate and earn extra. Just an option.