AdStage, a startup whose co-founder and CEO Sahil Jain said he plans on “bringing a real SaaS model to the ad tech space,” is announcing that it has raised a $6.25 million Series A. The company debuted at last year’s Launch conference, promising customers an easy way to create ads that run across Google, Bing, Facebook and LinkedIn. Later that year, AdStage announced a broader platform to extend the core product’s capabilities by integrating with outside tools and with apps created by AdStage itself.