We bought hard to find small packages from both Shontell and from the Timeshare Store (the sponsor). Our experience:
With Shontell, we spoke to her directly, told her we were looking for a 100 point package at BWV or BCV and she put us on an email listing and sent advance notice of hard to find packages (others were on this email list as well). This was how she operated about a year and a half ago, so I'm not sure how she does it now. I can't say for sure, but I also think she called and left a vm. That is how we found our original package.
For our 2nd package (looking for approx 50 points), we called The Timeshare Store and asked to be put on a 'waitlist'. I think I left a voicemail message. I think we alerted Shontell as well. We never heard anything back from the Timeshare Store. We were obviously not put on a call list because we just found the package on their web site. It actually sat there for almost a week while DH and I debated buying it. Once we decided, we called and it was ours. We have passed ROFR and are closing momentarily. Since we found our package, I haven't seen much in the way of 50 points esp. at BWV and BCV, but they definitely do come and go.
My advice is to both check the web sites daily (there are some others out there as well - we actually almost bought from another one - Lee somebody, but the sellers had an issue so we didn't go through. No problems with Lee and his company though.
If you want to make call lists, I feel confident with Shontell that she will do that, but she doesn't get as many packages as the Timeshare Store. If you want to be on a call list for the Timeshare Store, call there and make sure you get a live person and make sure they understand to call you. I guess bug them. Otherwise, like I said, just keep checking the web sites. Good luck!