Honestly, I think it is the assumption of most men that any never-married, childless woman wants to be married. I don't think it is something that needs to be discussed at length. But I think in an online dating/speed dating/personals dating/matchmaking situation, it makes perfect sense to briefly ask the guy, before you meet or on the first date in the getting-to-know-you phase, what he's looking for out of this.
But don't expect these gys to always be honest or even know, themselves. And just bc they say they are open to marriage, that isn't an assurance they are open to it with you.
Just take any "yes" response with a grain of salt. And believe a "no" response! LOL
Personally, I would not ask a man after a month "where is this relationship heading?"
I woud hate to be asked that!
How would he know after a month??
And you can guage it pretty well by his behavior.