Clearly , many big advertisers are still believers : last week , facebook shares got a boost from reports that walmart , samsung and other boldfaced names have recently stepped up social-media advertising .

很明显，不少大型广告商仍然相信社交网络的商机：上星期，facebook股价上扬，因为沃尔玛、三星和其他大品牌公司近期加大社交媒体广告投入的消息产生利好。