Why not a Fight Aging! book? Why not indeed; after all, it would seem I have enough material to pull together (or the head of steam to write even more) for the job, and a point to be made that can be expressed in a paragraph:
We stand within striking distance of the defeat of aging - the defeat of frailty, disease and disability with advancing years. The future of our healthy longevity is up to us. That future depends upon our banding together to provide successful support for the best and most efficient paths forward to real anti-aging, rejuvenation medicine. Oh, and you'll help your own personal chances of living to see this future by some modest amount if you are sensible and proactive about health matters - but the payoff from that effort pales in significance compared to the payoff from your support for research.
Looking back, I have managed to continue to find somewhat novel ways of saying this for something approaching five years now. No signs of letting up yet, as I haven't stumbled upon that magic formulation that will stop the world while everyone listens. But in any case, yes, folks in the online space have pulled together books from less of a start.
But I don't intend to pull together a book.
If a blog post is a short conversation, a book is a big gala presentation; both are essentially one-off short-term events, but it takes a lot of preparation and work to put a book out into the world and make it worth the while. The writing is really the least of it - what makes a book successful is the same thing that makes any gala event successful: networking, marketing, public awareness and reputation. For example, Kurzweil's more recent books have been successful in putting ideas out to the world and into the public conversation not because of the topics, quality of writing, novelty, or any other aspect of the books themselves. They rode on the back of Kurzweil's name recognition, his brand, and the level of marketing that a publisher was willing to invest in that brand - an example of using a reputation to make the points you want to make, writ large upon the broadest stage you can reach. Nothing wrong with that: Kurzweil's return on the investment of his time was large.
In my case, you have to look at what I am trying to achieve: larger and more energetic activist and advocacy communities, primarily, and then more rapid progress towards longer, healthier lives by the most effective methods. It is cost effective for me to write blog posts, provide a news service, put together modest resources for beginners, and cast them all upon the waters to sail in search of an audience. The modern structure of communication tools and culture has made everyone a publisher for fees measured in nickles and dimes, after all. If a post fails to engage anyone and sinks without trace, I have lost little. There will be another tomorrow, and new channels and methods of communication to explore in the next month. It was RSS aggregators back when I started, and it's social news networks now - and it'll be something else next year, helping to make it more cost effective for me to bring people around to my point of view by doing exactly what I am doing here.
But a book - that's a large amount of effort to put on one roll of the dice. Even if I succeeded to the plausible best of my ability, it wouldn't be all that impressive in terms of obtaining the results I value. Another book in a sea of books, nothing to distinguish it from all the others, nothing to bring in the crowds to listen and be persuaded - a mere pebble dropped in the pond, and then gone to the bottom. Don't write a book unless you're already famous somewhere, that's my advice. The rest of us are better off blogging, slow and steady, to build an ongoing persuasive conversation and resource for our cause over time.