I think you could easily go both directions. It may very well depend on the volume of deals you're doing, and how many people are on your buyers list. It can be really easy to develop a great relationship with 4-5 buyers who you know will most likely buy your deal. That's great if you want to continue to make similar amounts on each deal, seeing as that is what the buyer becomes accustomed to. Of course, there are regular buyers who don't really care what you make.
If you're doing 4-5 deals a month, with a buyers list of 500, then you most likely don't want to be sending personal emails or texts. Of course, you can always give certain people a heads up. However, I wouldn't sell yourself short by only selling to a few people. What if you come across other buyers that are willing to pay more? It's a tough balance and a good question.
#2, but I'd definitely mix in #1 if you have certain buyers that consistently approach you about deals.