It's certainly my hope to be cost effective, but I understand the worry and I'm sorry that you had that experience with the PMs of that time. At the end of the day, I see my target customers as those who aren't interested in running their own infrastructure and having to manage availability and durability (in memcached case, things like needing to pre-warm the cache). I understand that it still may be possible to be more cost effective if you're willing to trade off ease of use for dealing with those other concerns.