A couple of things about how to connect with your customers/end users.
Each channel has a specific target audience and people expect different things from each.
They want to know about it as soon as it happens. Keep it up to date and quick.
They want to know about it AND they want their friends to see that they like it.
Users don't want to commit to it right now but they do not want to forget about it. Keep e-mails to a minimum and remind users about it every now and then.
Clear, descriptive titles for whatever you publish (RSS readers usually show titles only).
Always remember each time you ping your users costs them time; time is limited and the more you publish, the less value each individual post/update has. If your content isn't relevant for them (i.e. it's pure marketing) or if it's too frequent (depending upon the medium of choice) they will simply start ignoring it eventually.