mySimpleAds works without a hitch. I actually tired an open source alternative and was left scratching my head to figure out how to make it work correctly. I also tried another paid version before buying mySimpleAds. I'm impressed with the software.
The program is solid.
While simple to use and to figure out, it runs runs quickly, delivers ads without a hitch. In the month or so since installing the script, I've delivered over 400,000 ad impressions on a shared server without a single problem. I'm even using it to deliver content blocks to other sites that I own.