Startup Metrics for Pirates: AARRR! by Dave McClure

Dave McClure likes to hang out with entrepreneurs, and occasionally help or invest in their startups if they let him. Dave has been geeking out in Silicon Valley for over twenty years, and has worked with companies such as PayPal, Mint, Founders Fund, Facebook, LinkedIn, SlideShare, Twilio, Simply Hired, O'Reilly Media, Intel, & Microsoft. Many years ago he used to do real work like coding or marketing or running conferences, but these days he mostly does useless stuff like sending lots of email, blogging, and hanging out on Facebook and Twitter. Dave also likes to play ultimate frisbee when his knees don't hurt.
[from Dave's bio]