This paper analyzes the impact of a large scale randomized experiment that targets firm labor demand by supporting its recruitment practices. We evaluate the effect of a Public Employment Service’s (PES) intensive firm prospection campaign in which free recruitment services were proposed to a large number of small and medium sized firms in France. We find large impacts of this new active labor market policy: a 30% increase in vacancy postings with the PES and a 9% increase in permanent contract hires, translating into 48 more workdays created by treated firms on average over a sixmonth period. We find that these results are not driven by intertemporal substitution and that job creation impacts are centered in slack labor markets, suggesting that firm level displacement effects are likely minimal. We confront a simple model of firm search for candidates against data on vacancy characteristics and services delivered to these vacancies by the PES. We find non-experimental evidence that candidate prescreening may be a key component of the intervention because it reduces matching frictions associated with slack labor markets. Finally, the intervention might be significantly more cost-effective in low-demand labor markets than traditional job-placement policies that focus on jobseekers. These results suggest that active labor market policies that focus on firm labor demand may be a valuable addition to the labor policy toolkit.