Seeing as the topic is stock photo zoom, we can chip in...

Magic Touch zooms images and can show a custom watermark. Combine the watermark feature with IP restriction and it becomes a very secure way of displaying high res stock images.

Try our watermark example.

See it live on the Shot Farm stock photo site.

It is low cost - from $9 per 20,000 zooms. Try the free trial.

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One way or another, zoom is an essential feature for maximising stock photo sales.