I read it somewhere, years ago. So I can't remember where. I think it was an academic paper about the interactions of traders with missionaries, where by claiming to be Christian the trader wins a sale (a conversion, you might even say). But I just did some searching, will this do?

https://norse-mythology.org/the-vikings-conversion-to-christ...

> Surely some cases involved genuine religious convictions; it would be superficial and reductionistic to assume otherwise.[18] However, it seems that the majority of conversions occurred largely, and perhaps entirely, for the sake of the tangible, practical advantages that the new religion brought with it.

> [...] the Norse seem to have become convinced of the might of the Christian god largely through more down-to-earth political and economic means.[21] Viking rulers – who, as we’ve noted, were generally the first to formally convert to Christianity – wanted to forge alliances with the powerful Christian kingdoms to the south so as to consolidate their own power. The kings of those southerly kingdoms, in turn, were happy to oblige, as this enabled them to turn former enemies into pacified friends.[22] Viking kings also found that “the document-based church administration was unsurpassed and utterly useful to rule and administer a kingdom.”[23]