The creative key is to find the chief benefit your clients gain by hiring you and contrast that with what other companies without your services are losing. 

For example, if you help retailers increase their sales per square foot, illustrate that benefit with headlines and visuals that underscore it. As for the media choices you've made, it may be that the publications didn't pinpoint the target audience finely enough. 

Focus on your best prospects and target them with the media they look to for information on increasing their sales and profitability. Avoid general consumer or business media. You might want to go after your target audiences vertically by using industry-specific media. 

And consider using direct mail and online paid search campaigns in partnership with print advertising.