Hitch actually does exactly what he early claimed he does for Albert. His pitch involves telling the men to be themselves ("If you're confident, be confident. If you're shy, be shy") and as he said to Allegra earlier in the scene, she never would have noticed Albert if it wasn't for him. This is only a shocking revelation to Hitch because, as he was called out earlier, he doesn't believe his own pitch.
After Hitch's story is printed in the paper, we see one couple approach him, the woman suspicious that her boyfriend used Hitch's services to hook up with her. How many other perfectly happy couples across the city do you think are likely in the exact situation, and you know that not all of them are going to resolve it peacefully.