Shops can be posted to JobSlinger in three ways:

• From the SASSIE mystery shopping system (http://www.sassieshop.com/site/). Mystery shopping companies using SASSIE can choose the "Post to JobSlinger" option to post their shops, and also have access to JobSlinger ReachOut (to email JobSlinger members located close to hard-to-fill shops) and Recruiterator (a tool that makes it easy for JobSlinger Plus members to sign up as shoppers with your company).
• From the MSPA assignment board (http://www.jobslinger.com/mspa/exec/sfs/jobboard). MSPA members have the option to copy shops to JobSlinger when posting to the MSPA job board. Posting is available to MSPA members -- for more information on MSPA membership, see http://www.mysteryshop.org/join/.
• From the Volition job board (http://jobs.volition.com/exec/sfs/jobboard). All shops posted to the Volition job board are automatically posted on JobSlinger. For information on getting a scheduler account on Volition, see http://jobs.volition.com/exec/NeedAccount.

As for which option is best for you, it really depends on your shop volume and also on other needs. Please let me know if you have any more questions, and thanks for your interest in JobSlinger!