Book excerpt: Three years ago columnist and author Grace Dent joined new social network site Twitter, mainly as a place to dump her surplus jokes, rant about garbage TV and post exclusive j-pegs of her hot new toenail-varnish. But as every 're-tweet' and 'Follow Friday' saw her audience figures soar by tens of thousands, Dent found herself centre-stage in an all-consuming highly addictive social network revolution. One where the gags, gossip, scandal and backstabbing literally never stop. Here Dent takes a hilarious, acerbic look at what's really going on in Twitterworld; who's actually tweeting, who's really reading your tweets and what's behind the 140 character lies they tell. She looks at the highs and grotty lows of twitter addiction, the shameless social climbers, the friends you'll make and the ones you can't get bloody rid of, the barefaced bragging, the shameful celeb-stalking, and the truth about 'twanking', twitter cliques, angry 'twitchfork mobs' and dealing with trolls.