I have several sites in the same niche - education.
Pandalized: 1 large site = 1000's of pages, covering many topics, very popular, WAS in the top 3 search results for hundreds of keywords, several somewhat competitive and the site is mature (13 years old). Pages are content rich, 3 to 5 ads per page depending on length (all unobtrusive - no popups, layers, interstitials, audio, etc). No links ever bought or sold.
Non-pandalized: 5 other sites, much smaller (10-50 pages max) focused on a single specific subject ranked in the top 3 for the specific subject (2-5 keywords each), somewhat immature (3-5 years old). 1 to 2 non-obtrusive ads per page.
No video on any of the sites, nor on any of the sites that currently rank in the top 3. My site is unique in that it has dynamic and innovative useful content - and I feel google's algo can't understand the complex structure and value of the content I produce.
The sites that now rank in the top spots (and have since Feb) are small and very static (compared to mine). Some are very old and never updated, and one that stole my most profitable top spot is simply page with nothing but a single link to another page. The 2nd result is the page the first spot links to. Really Google?
One thing that is almost universal is that the top spots are now occupied by very small immature and mature sites with 1 banner or no advertising. Design is almost universally very poor and unprofessional (think just plain text and links - no images, maybe funky background colors). A few attempt to be dynamic in nature, but are amateur. The others are just static and limited in their value and "replay-ability".
This gives me the impression that my pandalized site covers too many subjects, contains too much content (which is too complex in nature for google's algo to understand), and has ads to support it (we don't sell anything).
We do have a decent Facebook following - about 7K after starting a facebook page a year ago.
Still looking for answers and making changes (completely blind of course).