Facebook's (META -0.22%) second-quarter revenue and profits came in much higher than Wall Street analysts were expecting, and shares had their biggest one-day gain ever. Mobile advertising now makes up 41% of Facebook's ad revenue. In the lead story on Investor Beat, Motley Fool analysts Jason Moser and David Hanson examine Facebook's historic day, the "next big thing" from the social network, and what it all means for investors.