The old adage seems to be holding some water for global mega brand Gillette this week, who ignored the idea that if you don’t have something nice to say, don’t say anything at all. It seems the consumer packaged goods giant decided to take the low road (or whatever the opposite of the high road for a gracefully aging brand might be) but letting some kind of jr associate social media manager run their Twitter account.As AdWeek reported, Gillette (after asking permission) promoted various tweets from unhappy users of Dollar Shave Club. You might remember the incredibly witty, unbelievably cheap and ultimately awesomely popular one take video of Dollar Shave Club founder and CEO Michael Dubin that has earned itself over 20 million views to date. The company has chugged along nicely ever since, launching three other personal care brands and continuing to grow its subscriber base among 20-35 year old men. Whatever it was Gillette had in mind with this campaign is almost certainly the opposite of what’s happened: Dubin and his crew probably feel pretty good, and Dollar Shave Club wins the sympathy vote based on the actions of the now malicious Gillette.How could a brand like Gillette, with its fancy advertising, star studded roster of spokesmen and still-memorable jingle slip up like this and what happened? Are there any leading brands that have successfully trolled their upstart competitors and seen it go well? We couldn’t find any examples.The takeaway here, for anyone creating, promoting or hoping to earn money off of content is simple: be nice. While there might be a time and place to opine, or to even push back against competitive product, campaigns which smear a competitor in any way rarely win and generally hurt brands more than they help. Gillette will feel this blowback in far greater proportion than they likely estimated possible, and savvy Twitter users saw right away exactly how disingenuous this campaign really was. And then voiced that. Immediately. Over… Twitter! Funny how that works.