I'm starting to think that I may have to prepare myself for dropping exclusivity at IS, not yet but sometime in the next year or so possibly. I'm disillusioned with the running of the site and feel they've lost direction. I'm not ready to yet but would like to be set up ready so, when the day comes, I can hit the ground running. Once the decision is made I will want to be on as many sites as possible. From the experiences of others here, is it possible to apply for other sites, get accepted, but not upload? I realise that's what happens at IS, you make the initial application, get accepted and then start uploading and being inspected. I don't want to apply to sites, get accepted and then find my work is immediately available. How do other sites work the application process?

I still have accounts - with nothing for sale - at several other sites. With SS, for example, you can set something in your profile to disable it, so that images can be uploaded but not externally visible. With the other sites there's no similar master switch (AFAIK), so files need to be disabled/enabled individually.

SS does inactivate your account after a certain time (I think it's 3 months) but e-mail to customer service will reactivate it (I did that once when the partner program was introduced, but calmed down when they made it optional).

The only other prep thing to consider is keywords in your images. If you've been keywording for the IS CV, handling synonyms and phrases is something you'll need to work on. So the IS search engine maps multiple terms to the CV one, so you only have to enter the CV term. For other sites, you need to include those synonyms if you want your images found - so sunshine, sunny, sunlight, sun all map to a choice of two CV terms Sun (Sky) and Sunlight (Light Effect) on IS. If your image contains only Sunlight, you need to add the synonyms. Handling of phrases varies a bit from site to site as well - I think SS needed quotes, for example.

Not sure about your choice of color space, but when I last uploaded elsewhere (August 2008) none of the sites handled images in spaces other than sRGB automatically. Thumbs in AdobeRGB look awful in a non color managed browser (or everywhere if whoever's making the thumbs doesn't include a profile). As a result I always converted my images to sRGB when making JPEGs for upload. I stopped doing that after I went exclusive, but unless something's changed at the other sites in the interim, would probably need to make new sRGB JPEGs for those in AdobeRGB so they don't have dingy looking thumbnails.

Indeed, it is possible.  I am exclusive at Dreamstime for a couple more days but I am submitting my images to a couple sites that allow me to disable them.  Once the exclusive contract expires, I will enable all the images and hit the ground running.