"Personal relationship with the brand" may not have been the best wordsmithing, but I think the OP meant something along the lines of "your history with buying

"Personal relationship with the brand" may not have been the best wordsmithing, but I think the OP meant something along the lines of "your history with buying and using other products made by the same company." Presumably if they had the manufacturing and QA processes in place to sell you high-quality goods before, those same processes should help make sure that what you're buying from them now is also reasonably high-quality. It's not foolproof, and of course there are exceptions (especially if the company has changed ownership), but it's a decent signal.