Rule #1 for beta invites: remind me what you do
scottkle.in
scottkle.in
I often get emails along the lines of: "Annoucement! Spluttr adds 25% more foo to free plans!" or similar.
Now I probably signed up to Spluttr 6 months ago, took a quick look and decided I wasn't interested as I needed 25% more foo.
In the intervening months, you've lived, breathed and sweated Spluttr whilst I've signed up for another 20 services and forgotten what most of them are for.
Remind me in every email.
Also, make sure you explain it clearly. Once I went to a site that had pictures of food all over it and it said "like AirBNB but for food". I could not remember at the time what AirBNB was.
That might be fine if I'm forwarding it to other people in the HN-type crowd, but I often tell my less tech-inclined friends about cool services I've started using. But I would never recommend something to my friends without being able to try it myself and work out if it is recommendation-worthy.
(There was a service advertised here a while back during the first wave of the social-queue-jumping fad - it said you could either get in immediately, or wait seven days. There was no way in heck the queue was that long; I ditched it and found something else.)
Going a step further, if you haven't seen me in a while (say a year), send me an email reminding me I have an account with you, and summarize what you've done in that time. Remind me of my username too. This is kind of a big deal, because I sign up for everything (can't have username dilution :) ). Just because I don't use your site now, doesn't mean I won't after your new features, so as long as it doesn't turn into spam, I like the reminder.
Amusing anecdote: I signed up for Reddit within a year of it's launch, but really start using my account there until 2.5 years or so ago when I decided to re-evaluate it. I had completely forgotten about my earlier signup and was real bummed when I learned of my username being taken. Fortunately I was smart enough to do my "It's probably me and I've just forgotten" ritual where I try all my password variants and sure enough either I really got lucky and the old sophacles had one of my passwords, or it really was me. I probably would have been actively redditing 2 years prior if there had been a not-to-spammy email reminder once in a while.
"The median visitor will arrive with their finger poised on the Back button. Think about your own experience: most links you follow lead to something lame. Anyone who has used the web for more than a couple weeks has been trained to click on Back after following a link. So your site has to say "Wait! Don't click on Back. This site isn't lame. Look at this, for example."
You can read the full article at: http://www.paulgraham.com/startuplessons.html
Is a one-liner enough (i.e. "We're a crowd-sourced record label!"), or would people prefer the whole spiel (i.e. "We're a crowd-sourced record label that does this, this and this!")?
For beta users, advisors and early investors - these people are going to be your advocates. You need to give them the tools to advocate for you, and a well crafted 3 sentence elevator pitch that describes your business is a huge help.
They're sure to remember you if you do this. You can even do automated email segmentation. If their reply has "Sent from my iPhone", you know you can send launch emails for the iPhone version to these guys. If their reply has "Sent from Droid", send the Android launch emails to them.
Starting a conversation also lessens the probability your launch email gets put in spam as well... I'm sure Gmail, Yahoo, etc all have algorithms where if you respond to an email address, any future emails from that email doesn't get marked as spam.
I guess it depends on the service offered (mine is file sharing for companies in french) but in that case interested users just don't seem to be willing to send an email after already taking the initiative to subscribe, confirming email etc.