Several microstock  sites could be described as "a paid stock photo collection with a small free collection on the side for marketing." PhotoXpress works the other way round - it is a free collection that also sells image subscriptions on the side for those who want better quality photography.
The site currently offers two image collections - it's simple for customers but causing some confusion for microstock contributors. The big draw for consumers / visitors is the free collection for more than 600,000 images.
First up: You can't upload your images to photoXpress, they are a fotolia  reseller. The free and 'lite' subscription images which are offered at low cost are NOT from the main fotolia collection, they consist of fotolias rejected images which were either donated or made available by fotolias photographers for this use. Of course Fotolia contributors can opt-out altogether from offering their images either for free or for reselling via subscription on sites like photoxpress.
When launched photoexpress only had a free collection, these were sourced as rejects from fotoila, and looking at the collection you'll see why they are available for free, there are some very good images in there, but also a lot of rubbish too. There are limits on the number of images that can be downloaded for free.
The other collection is sourced as a fotolia reseller (like pixmac), in fact photoexpress is owned by fotoilia. these images are only available via subscription and cannot be purchased or downloaded individually on photoXpress.
Photoxpress offers two levels of subscriptions:
- the 'lite' subscription offers more-or-less unlimited (15,000 images per month) access to the 'free collection' It's is available at very low cost from $9.99 a month. There are a few lite options the 'lite 1' offers one image from the premium per day in addition to the free collection access.
- The 'premium' subscription gives access to 6 million (at time or writing) images (the Fotolia microstock collection). A comparison of prices for the subscription on photoxpress and fotolia for example: 1 months at 25 images per day is the same cost on both sites at $199 (fotolia standard subscription).
It would be a bit of an exaggeration to call this site a watershed for microstock, but I'm certain a lot of people in the industry are watching this. For more of my thoughts on free stock images read my post "free microstock photos ". PhotoXpress is a good example of a site attracting visitors with a collection of some 600k free images and then offering a couple of options to convert these visitors into paying customers i.e. either a very low cost subscription to obtain more images or selling them up to a full priced subscription similar to that offered at fotolia itself.
As photo express don't accept images directly or sell individual images I've left various measurements I normally use to compare sites (for contributors) below blank for this review.