I feel your pain, Peter.  I do series all the time, but what I do is pick a couple at most from each - then submit them in the day's batch.  It's a little more work, but I don't mind.  Batch keywording is easy...then somedays you can submit batches without even having to do any new keywording.  Take a couple from this series, a couple from that series, and you're good to go.  You also lengthen the exposure you get for any one given subject.  Mainly, you get to avoid the rejections.  Reviewers in general will just pick the best 2 or 3 in the series, then reject the rest. 

re-inspecting all images (on todays criteria) older than 18 months would be best solution.

only if you assume reviews are consistent -- if an old image is rejected on second review it could just be the reviewer

ideally no image should be rejected by a single reviewer - it should have at least 1 additional review.  in any other situation this would be a no brainer, but when an agency is dealing with thousands of images a day they just cant afford it.

  this is a type ii errorhttp://en.wikipedia.org/wiki/Type_I_and_type_II_errors

it's better overall to accept that there will be false negative [rejecting good images] rather than accepting type i errors [which is what sites like most, cut, yay et al do by accepting just about anything]

it's possible to keep both types of error low, but it's much more expensive and only used where it's critical.  we see examples of this every day, but often the choice between the 2 types isnt acknowledged -- eg, death penalty laws, rules of engagement re civilian casualties.  for a much less important case like selecting pretty pictures, it's no surprise how the agencies react

Not speaking about just Fotolia, but it's not a bad idea to keep a folder of similars and when the originals start to lose momentum, push through a fresh batch.  I remember Sy posting that once during a slow period she went through old folders and came up with many new submissions and was rewarded with sales.

I usually do exactly that. And it works well for me - especially on SS.

I'm starting to believe that they just randomly click and don't even look at the images anymore, especially when it comes down to the keywording. FT is so far my least favourite for allowing keyword abuse. Perfect example is this picture with an invisible buffalo dog playing a trumpet. http://en.fotolia.com/id/9925180

Wow!  How many keywords to they ALLOW at Fotolia?!  That looks like the entire dictionary attached to that one. 

I'm starting to believe that they just randomly click and don't even look at the images anymore, especially when it comes down to the keywording. FT is so far my least favourite for allowing keyword abuse. Perfect example is this picture with an invisible buffalo dog playing a trumpet. http://en.fotolia.com/id/9925180

wow, pretty girl.
but even bigger wow for the keywords. reads like the dead sea scroll. it would take me days to think up so many keywords 
that is if i don't fall asleep by my computer...

I'm starting to believe that they just randomly click and don't even look at the images anymore, especially when it comes down to the keywording. FT is so far my least favourite for allowing keyword abuse. Perfect example is this picture with an invisible buffalo dog playing a trumpet. http://en.fotolia.com/id/9925180

I couldn't believe this one! Out of curiosity, to see what the response would be, I tried raising this through Fotolia Support. After a little over 2 days they responded to say
"Thank you for your e-mail. We'll look into it." and they set the status on my issue to Closed. The image is still up and still has Buffalo and Trumpet etc?

 

I think everyone would be better served by deleting images with 0 or few sales over a given length of time. That could be done via software. A poor image is a poor image when judged by dollars spent. Don't need an army of inspectors either. Wise retailers would never have a poor selling item taking up shelf space. So why do our sites keep adding to the clutter?

This would be a good option ONLY when the search engine at Fotolia functions on par with the other sites.  Too many images aren't easily found there now!