Promoboxx, a startup offering a brand-to-retailer marketing platform, has raised an additional investment of $1.375 million to close its seed round of financing. The company's investors include Launch Capital, Boston Seed, SK Ventures, Common Angels, Stage 1 Ventures, and over 30 angels.

Promoboxx is a brand-to-retailer marketing platform that allows brands to launch co-branded, customized online campaigns with their retailers in order to strengthen relationships, localize national content, and reach more consumers.