jonah berger is the university of pennsylvania marking professor.e joke and the author of contagious, why things catch on. welcome. people share things that make them look good. this made me think of twitter. when i retweet something or share something on twitter that i think is funny or clever or interesting, part of me is thinking this is going to make me look clever and funny and interesting by retweeting it. a lot of us have that motion as we spread stuff around. explain how this helps going into making products popular and ideas catch o. >> sure. like the clothes way wear or the car we drive, what we say influences how people see us. you want to create an online persona. the same thing with off line word of mouth. with restaurants, people assume we are a foodie. we pick and choose what we say rather than to look bad g good or bad or easy ways to apply this. you want to help make them talk about your product in a way that reflects positive on them. things like google when they came out with gmail, it was hard to get. the people that had access t

. >> jonah berger thank you so much. we're sorry to have this cut shout.d justin over for lunch. good. no, not good. he's a vegetarian and he's going to be here in 20 minutes! [ mom ] don't stress. we can figure this out. ♪ ♪ [ male announcer ] get the speed to make a great first impression. call today to get u-verse high speed internet for as little as $14.95 a month for 12 months with a one-year price guarantee. this is delicious. ♪ ♪ [ male announcer ] save the day in an instant. at&t. ♪ ♪ >> your realtime captioner: linda marie macdonald >>> good morning, everyone. it's 8:55. i'm michelle griego with your kpix 5 headlines. >>> two arrests following a police standoff in san francisco's bayview district. police tell us it started with a robbery at a medical marijuana dispensary. they say there may be another suspect holed up near jennings and wallace. no injuries have been reported in the robbery or the standoff. >>> an accused drunk driver is due in court today to face charges that include vehicular manslaughter. 29-year-old kiran brewer of san francisc