Ads managed by TSL are from the folks under "Our Sponsors", including Campus Emporium, SERTC, etc.

The ads you're referring to come from Google, and they're different for every user. A lot of it is based on your browsing history, and the things "big brother" thinks you might be interested in. One person might see political ads, while another might see ads for shoes. TSL basically just "rents" that space to Google at rates determined by traffic on this site, etc.