I have asked the same question, if I can't procreate what will anyone see in me.
Most men, when reading this, will respond as Man@Home has done above (fertility isn't everything, you're still great etc), which is all completely correct and I'm not disagreeing - but I'd like to dig a little deeper.
I think there may be a disconnect between what is logically correct, and what men emotionally look for.
On the one hand, when I envision what I would want in a second wife, the woman I visualise is generally younger than my current wife (and therefore probably fertile by default). That's just what we imagine we want. That's why advertisements use women in their 20's when trying to sell stuff to men. We are hard-wired to FIRST think of a woman in that age bracket. Why? Ultimately, it comes back to biology - because a woman's years of peak fertility are from 16 to 26 (or thereabouts), our brains are designed to consider a woman in her 20's as optimal marriage material, to maximise the spread of our genes. That's both designed by God and reinforced by natural selection, it's just basic biology. So on a hormonal, emotional level, that's what we think of first.
So then, if we're going to make a list of what we're looking for in a woman to use to screen people on a dating website, for instance, that list is likely to include a preference for women in their 20's or possibly 30's.
It's not even because we want more kids (although it is for some men). It's just because of deeply ingrained assumptions that are based on biology reinforced by thousands of years of natural selection (we're all mostly descended from the men who had the most kids, i.e. the ones who married younger, as the ones who married older women left fewer descendants).
But the exact same man who writes "I'm looking for a woman aged under 40" when typing his human assumptions about what he's looking for in a wife, may be very interested in the real-world woman older than that who actually takes a real interest in him. Because his statement was based on his own imagination, which is inherently idealistic and biased. But his logical brain can see the value in an older woman, who has in many ways more to contribute to the family than a younger one, even being past childbearing age can be an advantage in many circumstances.
This means that when discussing this sort of thing on a forum like this, with the logical brain engaged, a man may type "don't be discouraged, there's nothing wrong with older women, you can make a great wife, hang in there". Then, with his emotional brain engaged, he may flick over to an internet dating site where he personally specifies that he's not actually interested in older women at all...
It's very easy to be hypocritical, to be over-encouraging to women in a setting like this and then not actually practice what we preach.
Just trying to be completely honest and find a balance here, because older women do face real challenges finding a husband, it's easy to offer words of encouragement but if we don't appreciate the actual issues here then our encouragement is hollow.
This is not a criticism of the above post, which I agree with, just some further musings.
so it would surely not apply to me 
