To give you a datapoint - personally I'd be more likely to read a significantly shorter summary, say 2-5 pages. I guess you'd reach a broader audience. The downside would be that the most interested people, who would read the whole thing, would miss some of the details. With many things I read I would often appreciate having a short version AND a longer, more detailed one actually, so having both would add value. All in all, I think you're doing valuable work.

Maybe also consider making a summary on Wikipedia or improving it. It may get many more viewers amongst other things (http://reducing-suffering.org/the-value-of-wikipedia-contributions-in-social-sciences). I'm not sure which option is better.

Btw: There's an Anki-deck for Cialdini's book. It might be somewhat less useful if you've only read the summary though, because you may have skipped some of the examples in it. (https://ankiweb.net/shared/info/2834764538)

I think it's a good idea to summarize books like this, and I found it well-executed.

In addition to commenting on what you think of the summary, it would be interesting to get feedback on how useful you think these sorts of summaries are. On one hand, I think in reading my summary you can, in a single sitting, get 90+ percent of what you'd get from reading the 200+ page book. The persuasion principles are also applied to animal activism, adding a new angle to the original book. On the other hand, how much is actually being gained here? Will the people that read this summary be people that already know this stuff? Should I bother writing more?

I'd be really keen for people to reflect on these questions, because I've considered contracting people to write more summaries of important books.