I was once told that using the same metadata across multiple clips only hurts you in searches.  I don't know if that's true anymore, but while sometimes I use the same keywords across multiple similar clips, I always try to mix up the titles and descriptions.

i use same metadata for similar sets

captioning images is the most time-consuming part of submitting microstock - i have thousands of images needing metadata, so if i can do multiple images at once, i can submit more. and at the $ we receive it isn�t worth the time to tweak  each image without knowing if any of them will sell

trying to game the system without knowing the rules of the game is a losing strategy, especially when each agent has its own secret  rules

Anyhow, I learnt that having different images from the same subject can be useful, but only if the image is... well a different take on the same subject. So to me it also makes sense then to have the differences reflected in the title and keywords.

Not sure it's really crucial, because buyers will see the related images in the section 'more from this contributor'.