Besides PPC there are several other ways to earn more revenue with SMS Alert Affiliate Program:

Provide a short Getting Started guide for your potential customers. This guide may include instructions on setting up a SMS Alert account and buying credit. This strategy has dramatically increased conversion rates for many of our affiliates.
Create custom banners that will appeal to your audience.
Add multiple SMS Alert buttons throughout your site or app.
Write comparative reviews highlighting why SMS Alert is your choice for SMS software.