Backlink strategies with high ROI?

Hey guys,

So my boss wants me to build backlinks. This is not what I specialise in as I am more content strategy and keyword focused.

However, I don’t want to let him down.

So far I have tried broken link-building with 0% ROI.

I’m fact all of these email outreach methods seem less than likely to pan out successfully.

I’m trying to promote our infographics as well but he’s not very convinced with that strategy.

Is there any method you can recommend for a website with no brand identity to start building links?