If you're new to link-building for SEO - this is a list of solid domains to build 'background noise' links with - natural looking links that register in ahrefs.

It's not an automated service, manual work is involved. But even if you find 10-20 solid domains to build backlinks from, its worth the low cost.

I had some very minor issues registering from appsumo - but after logging out of my test account then logging back in again, it redeemed absolutely fine.

Worth investing in, especially if you're willing to put the time into building the links.