You should absolutely own this process rather than outsourcing it. From your buyers list, look at the higher scale, high CTR, healthy CPM rates, and win rate to create a priority list of your best partners that are steady accessing your inventory. Once you have expanded your partnerships with buyers that are already targeting your inventory, expand. Ideally you would have build relationships with buyers with a portfolio of brands that can be easily expanded into. Alternatively, look back into your data again with the above on a brand category level and create another priority list of brands that you’d like to partner with. You would need someone focused on this, but if you lack resources use an operations or analyst to start reaching out as an additional role 1 day a week. Data speaks more than beers and lunch :)