targeting technology (marketed as iSense by ad pepper media) and brand protection technology (marketed as SiteScreen by Emediate ApS). The iSense technology is the subject of patents in the United Kingdom and the United States. After the company's acquisition by Ad Pepper Media N.V., he remained on the board as its R&D director until 2009.

Crystal was influential in a campaign to save Holyhead's convent from demolition, leading to the creation of the Ucheldre Centre.