IRCTC (Indian Railways' ticketing website) does this. Here's the brochure for their service: https://contents.irctc.co.in/en/Captcha_Advertisement.pdf https://c

IRCTC (Indian Railways' ticketing website) does this. Here's the brochure for their service: https://contents.irctc.co.in/en/Captcha_Advertisement.pdf https://contents.irctc.co.in/en/Captcha_Advertisement.pdf Product page from the vendor: https://nlpcaptcha.in/en/nlpcaptcha.html https://nlpcaptcha.in/en/nlpcaptcha.html >Simpli5d technologies makes Captcha an integral part of their products. They provide an engaging Captcha for brands wherein the user engages with the brand by filling the brand message or engaging with the brand across its publisher reach to ensure two way real human engagement with the brand. > Further, this is not just restricted to Captcha and Simpli5d also provides similar solutions on Video pre-roll to ensure there is two way engagement with the brand in the pre-roll as well and not just restricted to blind video views. In general in a video pre-roll campaign the brand is not sure if the video has in reality attracted the eyeballs of the consumer. All these solutions are also available on mobile.