New York—Social microblogging company Tumblr has begun rolling out mobile ads that appear as sponsored posts rather than banners. The new, mobile “native ads” will appear as text but will be differentiated by a small dollar sign icon. The ads will appear to users of iPhone and Android mobile devices up to four times a day, with viewers able to “like” or reblog them, the company said on its blog. Initial advertisers include ABC Entertainment, General Electric Co., PepsiCo Inc. and Warner Bros. Entertainment.