It probably will make your blush last longer, but I wouldn't expect any miracles. Get a sample, if you can to test it before you buy.
Also, to make your blush last longer and appear more vibrant during the day, apply a cream blush (like BB's Pot Rouge) where you normally would apply it, then your powder and then your regular powder blush on top. That will make the color last longer and appear more vibrant (not clownish though, don't worry)