Atemi Group is described by its new acquirer as one of the world's largest companies specialised within lead generation for online gaming through paid media and social media advertising.
Of the total, £32.5m ($41.9m) will be paid up front; the remaining £7.5m will be paid in equal quarterly deferred payments until the end of 2021.
Better Collective's main strategic objectives for the takeover include access to key traffic acquisition channels, access to key social media platforms, the opportunity to expand in new markets and the chance to significantly uplift its new depositing customer volume.
Better Collective CEO Jesper Søgaard said: "This acquisition is a very important step for us to reach our strategic target of becoming the leading sports betting aggregator in the world.
"Atemi Group has been on an impressive growth journey since the company was founded in 2015, and has reached the large scale it takes to be competitive and profitable within paid media."
Atemi Group founder Richard Skelhorn said: "We built a very successful gaming affiliate business over the past five years at Atemi.
"All credit goes to the amazing team and now we are thrilled to be joining Better Collective. I am certain this will take us to the next level.”