Very thin line between saying ''If you don't have sex with me something nasty will happen'' and ''If you do have sex with me something nice will happen'' ie. promotion at work, better grades for a student, direct money payment etc. The last cases are all cases of prostitution no different to what happens on the Reeperbahn, though less honest. In the first cases - if physical danger is involved, or if the woman is inebriated at the time (through whatever cause) and incapable of rational consent, then it is rape - if not eg. 'do it or I will destroy your career' then it is not technically rape but surely qualifies as criminal nonetheless, almost in the same way that blackmail could be used as a lever.