We get an explaination what AIM is. It is what an Esper gives off involuntatarily. In Accelerator's case it is his redirection of everything including gravity. With it Esper abilities can be measured.
But in the case of Kamijou Touma it can't be measured.
Also we get a scientific hypothesis as to why girls are flocking to Touma.
In Touma's case it diffuses all luck and supernatural ability but it may also explain his luck with girls. LOL