I don't want to go into details, but I'll say what we didn't do. We didn't spam and we didn't do anything that we wouldn't want done to ourselves. We just got creative with advertising.
I agree with zkinion, many startups use "legal spam". Our site was around before MySpace became the social networking behemoth that it is today. They used to make fake accounts on our site all the time. And we would do it back to them.
You don't read about it much in the stories in Founders at Work, but from what I've seen a lot of very successful sites did whatever they had to do to win. If your product is truly disruptive you shouldn't have to do much at all to advertise it. But there are a lot of social sites out there, and a lot of them play dirty.
"If your product is truly disruptive you shouldn't have to do much at all to advertise it" - this is a the exception - in almost all case you have to so a lot to get the word out - it does not have to be traditional advertising but reaching your audience requires continues effort.
careful with 'do anything' - in certain cases if found out it will badly burn you and your organisation - e.g. Holden Karnofsky getting badly burnt after astroturfing MetaFilter over Xmas and the fallout that GiveWell then had to deal with. That won't apply to a lot of HN readers and their startups, but be careful - if trust is going to be a big part of your identity, don't be evil (there are always digital traces to come bite you in the ass)
Honestly, if that's one of the methods one chooses to get a startup off the ground, I have no problem with it. It's a small moral price a startup has to pay to get some momentum going, and without initial momentum, you really can't go anywhere. Sure, it's an annoyance on the user end, but if it's a truly useful service, I see no problem. Every user, especially in the initial stages, is valuable.
I have to spend a not small part of my time dealing with various forms of spam, and dealing with people that hate dealing with spam, and dealing with people that hate missing out on something because somebody somewhere was dealing with spam on their behalf.
I guess it would be easy to say, "Eh, what's the big deal?" if you never have to deal with the cumulative effects of everyone promoting their products in spammy ways.
At the very least, it's disrespectful to the folks that don't get paid enough to keep all the networks running everywhere.
Well, that may be true. But from the perspective of one trying to gain a little traction, spamming might serve well, especially after hearing that the persons behind facebook and plentyoffish probably used the same tactics.
That sounds like you used some "morally questionable" methods.. ?
Maybe you'd care to elaborate?