Online Advertising with Spatial Interactions

Researchers have developed a new AI framework for online advertising that accounts for 'spatial externalities'—how nearby ads affect each other's value. For a key model, they created a polynomial-time algorithm with a constant-factor approximation guarantee, proving it's truthful. In structured 2D space, they achieved a Polynomial-Time Approximation Scheme (PTAS). However, for a more complex model, they proved strong hardness, showing no efficient solution exists unless P=NP.