Just resubmit and leave a note to the reviewer that you have addressed all the issues noted on the previous rejection.  That's usually all that's needed.  Don't be surprised, however, if some of the images get rejected for a different reason.  That seems to happen more often than it should.

Yes, you really have to add a not, to avoid a warning from SS.  I just got a batch of 20 accepted for 50%, the other 50% was refused again, but for different reasons.

Did Shutterstock make any claims about market share and/or market share growth?

I will reapply soon, thanks for the advice!
I guess I don't really understand why they rejected my images, so it would be great to get someone's opinion on some of my rejected images. The reason I got was "poor lighting" on all of them. If anyone can give me more detail on what they mean, please let me know how you would fix the issue to get them approved:
http://www.mostphotos.com/7100952/attractive-blond-woman-taking-her-pulse
http://www.mostphotos.com/7100976/friendship-and-fitness-in-the-parc
http://www.mostphotos.com/7101004/group-of-3-women-doing-yoga-in-nature

thanks 

honestly I don't see much problems in them, 1st you do have a blown out highlight behind her head (I would resubmit, reviewer had a rough day!), 2nd picture same thing but much more severe (the very shallow DOF is fine but it is kind of distracting maybe because it is too much and somehow the angle on the picture doesn't help as well), 3rd same issues but once again I don't see much problem, there is a ball on her hands that you can clean out though

there are tons of pictures like yours online so this kind of photography is definitely appreciated, just give them another try

Thanks luissantos,
I was surprised that the images were rejected as well especially since a previous batch of the same shoot had been accepted at 100% so I send a request for a reevaluation of my batch (like the SS person had suggested to do on this forum for random rejections) and I got the same answer.
I guess I'll try again but the world of stock works in mysterious ways 

suggestions from anyone else on how to improve the images?

tx!

don't know what equipment you were using but a big reflector on the 1st picture would have make a big difference on her face etc