so, it is all reference towards, he was act trackive, he was intelligence, and couples who end up referring to the other person, and then to the diad more to themselves, that's an indicator they are focused on the relationship. >> reporter: back at the restaurant, dinner is over. they've put up with our cameras and say eharmony has worked for them. the question is, how well? i'm going to put you on the spot. is this relationship headed to marriage? >> yeah, i think -- hopefully. >> reporter: she's nodding yes. >> yeah, i know. i know. >> maybe i shouldn't be nodding yes. >> yeah, no, it's going great. i mean, i love her, and, yeah, i -- i can't imagine being with anybody else at this point, so, i would say definitely, yeah. >> reporter: they say love comes in many forms. eharmony's version starts with a line of computer code, and doesn't always work. but when it does, it ends up looking just like this. i'm neal karlinsky for "nightline" in pasadena, california. >> hmm. of course, the secret formula comes at a cost. about $60 a month. finding a soulful mate is priceless. >>> when we come bac