I understand that this question has been asked a few times on stackoverflow. 
However, I am looking for something more advanced here.

My clients app is basically an e-commerce app that has about 40-50 sales at a time. And within a given sale, there are between 100-300 products.

Given the number of images, each approximately 150x200pi in size, I need to get these to load faster.

I am already using SDWebImage library for fetching images. ( I have even tried AfNetworking and Apple's LazyLoadImages). 
I am pre-fetching some images when possible. But the client still needs it to be faster. I have seen some apps like Amazon's My Habit ios app load images almost seamlessly. I am still not close to that.

Given the sheer number of images it is hard to predict which ones to prefetch, it is not possible to predict what the user might choose to see.

Any suggestions much appreciated.

Thanks.