Twitter is giving away free advertising credits to US small businesses. On their blog they posted:
Since we launched Twitter Ads for small business in February, thousands of U.S. business owners have used Twitter advertising to quickly gain new followers, reach new customers and drive more traffic. In support of the Shop Small initiative and Small Business Saturday (#SmallBizSat) this weekend, we are giving away up to $1 million in free advertising credits to new advertisers. The first 10,000 eligible small business advertisers based in the U.S. will receive $100 in free Twitter advertising credits that can be used for Promoted Tweets and Promoted Accounts.