The present invention provides a thermoelectric conversion element that has high efficiency even at reduced thickness. The claimed subject matter provides a method and system from which an advertisement may be evaluated according to various metrics to determine a quality relative to other advertisements. These hairy polymer particles are comprised of a core which is comprised of a polymer of a vinyl aromatic monomer and hairs which are polymer chains of a conjugated diolefin monomer, wherein the hairs are covalently bonded to the core.