1. Calls to action below the marquee, showing plus icons to expand.
2. First box expanded, now shows minus icon, and call to action text with arrow.
3. Second box expanded.
Pano Logic sells a simple network PC. Their product site features a large graphic of the product, and 3 simple informational modules at the bottom to find out more about the product, read reviews and press, and watch a demo webinar. The modules expand when the user hovers over each box. There isn't much information added, except for a call to action that tells the user a little more about what they'll see if they click the link.
Very simple expand/collapse transition that can be used to highlight a call to action and display more below the surface.