Do NOT share non-watermarked images!!! Exclusive or not exclusive, doesn't matter...you should make sure that not posting even a single non-watermarked image outside of stock photo websites. People buy your image only because they want to get the watermark removed. If you supply without watermark, it becomes more of a "free image". Anybody would pick it up. Upload non-watermarked images to Dreamstime. They put their own watermark automatically.
The main concept of stock websites is...buyers see the watermarked file...and then they pay for the non-watermarked version. So you can put your own watermark too. But just have something on it. :)
Exclusivity - it means you cannot sell via any other agency. You're not restricted in other ways. Just make sure no third party is helping you sell your exclusive images.
55-250mm standard lenses. Dual tube macro flash and external speedlit...
Quoted Message: do we upload with our watermark or without?
Hi, do not add your own watermark. DT supplies the image with watermarks once they are approved. Adding your own watermark will just lead to rejections. Also don't add frames/drop shadows to your images.
Exploring a bit more both questions: About exclusivity You are the owner of the copyrights, so you can post your images wherever you want, you just cannot sell it through another agency.
About watermarks The ones you upload here, do it without the watermark as everybody said or they will be rejected. The ones you upload in your tumblr or wherever in the web, its really your call. My opinion is: If it is an image I am selling here, I just dont upload it anywhere, there is a big chance it will be stolen. If its an image I am not selling here. I upload them with a small watermark with my name in the bottom and a "hidden" almost invisible watermark in the middle. The intention is not really to make them unusable, many of them probably will get copied, but if they do they will still carry my name, so its kind of a way to advertise me. The hidden watermark is really if I am so mad with the thief I want to sue him. Normally if I find some of mine in a blog or webpage, I just report it and they remove it. The way I do my watermarks make them really complicated to erase, hard photoshop work would be needed, so I dont think the thieves would bother. Normally they are not doing that on purpose, at least I hope they aren´t :)
Check out my Google+ page and you will understand what I am talking about.