The secondary dimensions of an expanding ad unit (after the ad is expanded). Initial dimensions are fit to the dimensions of the placement. Then, either by auto-play or by user interaction, the ad unit expands to its secondary dimension.
Jargon Buster
Financial Conduct Authority (FCA)
The FCA regulates the financial services industry in the UK. Included n the FCA's remit is regulation of financial product marketing. The FCA have produced guidance on financial promotions in general, and also on social media. The guidance covers character limitations, the use of images, non-intended recipients and consumers forwarding or sharing communications.