IMO, just use the total, so thus far TLJ has grossed over 1.2billion; it's expected to creep over 1.3billion.
Google tells me it cost 200million to make. So even if we double that (for marketing and whatnot) to 400million and using basic maths, that's a profit of around 900million dollars.
Don't know about anyone else, but 900mil in profits spells financial success to me. This is also not factoring in merchandising, DVD and digital sales, which will probably bring in another 300-500mil.
edit: But also, should be noted that TFA made a bit over 2billion and if we compare TLJ to that specifically, sure, it was hugely less successful, but still a very successful film.