A couple of things about how to connect with your customers/end users.
Each channel/medium has a specific target audience and people expect different things from each.
Less is sometimes more
If your content isn't relevant for your audience (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.
If your content is active, keep the number of pings low; if your content is passive, quantity is your friend.
If you actively push information or updates to your users, you may want to reduce the number of pings and keep each post very relevant (each time you ping your users costs them attention; the more you publish, the less value each individual post/update has.)
If users come to you for information, then you need to have as much content as you possibly can; the more information you have, the more likely they will find you (e.g. via search engines, link referrals, etc)
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.
Email Newsletters for non-clients
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).