So you're getting a few conversions and you optimized to get a few more....but how do you scale even more?
Build out other angles, or move the offer to another traffic source and begin testing there.
Depends on the source, and the way you are promoting the offer. If you give us more of an idea on what you are wanting to scale, we can help more
.
You can scale to different countries, different traffic sources, try new angles with new demographics, etc....
increase your bid n budget.

^^^ only if ROI stays stable or the net daily increases.
Lucrumnet
there are only 2 ways to scale
1. get more traffic
2. optimize your path