I am married and could do with an extra £1000 a year. However, the cost of my marriage exceeded £1000 by several times, so being offered £1000 to get married is no incentive to someone in my position.
My incentive was that I love my wife.
Given these circumstances, I cannot see how "Dave" offering my £1000 a year to vote Conservative would influence me to get married if I wasn't already going to do it. All it is, in my view, is a cynical attempt to buy votes from those who are already married.
The alternative view also is that it terribly interventionist, attempting to tell people how to live their lives and all rather "preachy". Don't the Tories claim to be for the market, laissez-faire, less nanny state ? To my mind the Tory policy proposal announced today goes against all these principles.