It's fairly subjective at this stage, and is more of a judgment call than a science. I went with the following assumptions while putting down the 25% metric: *

It's fairly subjective at this stage, and is more of a judgment call than a science. I went with the following assumptions while putting down the 25% metric: * Conversion rates on vanilla sign up pages (with not a lot on the page) are generally not that high. I'd read that 8-10% was common. * Users already searching for charades online would be motivated to check out the ad (in my mind, this justified looking at a higher rate) * Since this was SCM based, it was not granular from a demographic perspective - likely had a mix of early adopters, mainstream users, etc. Hope this helps. I'd love to hear how others are doing this.