I know some of you will not agree, but I do have extremely good results with FB Groups and less success with email marketing.
1) Everyone is on Facebook
2) Groups are free to set up and run
3) Groups are social
4) People want to be a part of a group
5) Groups are viral
6) People get notifications of a group post if your posts are good they´ll check it out.
7) Groups are less aggressive - You don´t need to be aggressive with your marketing and groups lets you soft sell.
8) People don´t unsubscribe from a group if you offer good value
9) You can interact with your group - If they know you they´l buy what you recommend
10) Your posts will not end up in the spam folder
11) You can build your audience ultra fast for free