This was very helpful and thanks for publishing. Right near the end you just touched upon what i think is an important topic (perhaps its own post) If you could chart it your first exposure to John's (or anyones) audience is probably 80% of the bang for the buck. Sponsoring again 4 to 6 months later really only exposes you to net new readers since your first exposure or those that missed your first exposure and/or weren't a good target then but are now. If John is charging the same amount for each sponsorship the pricing model is broken for both of you. It sounds like you're underpaying for the 1st one and overpaying for additional and vice a versa for John. In general it's just something worth noting for anyone who advertises via such distinct channels (Imagine if HN let you do the same thing how your traffic and sales would be impacted by the 1st time you were on the homepage for 8 hours vs if you did it again 3 months later)
This is a great point and something that I thought was going to "pay off" but didn't. The results were significantly different but still beneficial... what I should have done is waited a few more months to dive in.
Will I do this again? Probably... but not until a major release, like a 2.0...
On the other hand, repetitive ads are less interesting for the reader (at least, I feel that way when reading DF), so they have a higher 'cost' to Gruber. Though this is more relevant to multiple consecutive sponsorships than a few of them spread over months.
