Every new Job board needs multiple revenue streams.
You can no longer rely on just job postings to earn income. You need to think of additional ways to add to the bottom line.
For example I still own twenty different niche job sites such as Parttimehires.com and Weekendjobhunt.com. These are Jobamatic sites which mean they come with 2 revenue pieces built in: Postings Plus Backfill. And I put Adsense blocks on the sites as a third revenue stream.
Between those 20 sites I generate about $1,500 per month. Each of the three revenue streams account for approximately 1/3 of that amount.
When you put google adsense on your site its like free money! Dont shun their ads, embrace them. Many high traffic websites use them and so should you. The key to adsesnse success is to expertly integrate them into your site design. That usually means using the same colors on the page. In the 13+ years that I ran AllCountyJobs I made over $200k in Adsense earnings. So put them up and you will be rewarded (as long as you have traffic).
BONUS TIP: check out this book about maximizing your Adsense ads
Think about other ways to earn money such as banner ads. Approach local resume writers or career coaches and see if they want to advertise with you.
The point is dont rely on just job postings. Diversify your income as much as possible. As time goes by it will add up into more $$$.