Meet & Greets are always good to get/stay connected with your fanbase, so I would never say she should stop doing those. However, I wouldn't credit them for her 2010 success, that was clearly the BET show and hit R&B single! She can't only be doing that and expect the album to sell itself.
Sis has plenty time though, it's not coming until late November or later. She is gonna give a 35k-55k first week.