DrFoxtrot, I find them to be useful. I know some people get uppity at the notion that they can be put in to one of only 16 boxes, and I know we're all snowflakes yes yes yes, but MBPTIs are useful!!!! Just as a guide. I'm not exactly like my type as I'm not that caring but I WAS.
Dr Creepy was ESFP so I'd high hopes that he'd be as entertaining in real life as he was on line, but no, we sat in virtual silence. Odd. With him as an exception I've found them to be a real headsup as to whether i'll 1) click with somebody, and 2) why it;ll end! and so far, it's been right with the exception of dr creepy, if I've known their MBPT that is. Really gives you a clue to potential pitfalls, and it helps me take things less personally. eg, H was entj and very focused on me at the beginning, and like an entj, he did quiz me about my future plans and intentions and also he motivated me and propelled me to get on with a few things I'd been procrastinating over, but as soon as he decided we weren't right, he was outa my life at a million miles an hour. Reading how entjs are in their romantic lives it really helped take the sting out of it. I knew it wasn't personal and that helped me deal with what could otherwise have seemed like an awful rejection.
Mr Canceller was infj and apparently they're guarded, have trust issues, are cautious in romance............ and, sure enough, he cracked jokes all the time, deflected personal questions, and then he reprimanded me for not responding to his messages quickly enough and said in a huff 'dinner isn't a good idea''. I don't know if he wanted me to change his mind because he'd said what music he would have played and what dish he would have cooked.
B is an enfp and they're free spirits and can't commit! They like to keep their options open, apparently. Well, again, that sounds like him. They only want to be with somebody mystical who intrigues them, and /or somebody they can't really have apparently. somebody, I don't know, in prison for example, some body who lives in a different country.
Dr Creepy and I might have got on better if he'd had a fucking drink and relaxed and stopped taking so many calls on his mobile! weird.