I think it's unreasonably low too, but haven't figured out a way to solve it. You can benefit by signing up other users, but this is not a very often used feat

I think it's unreasonably low too, but haven't figured out a way to solve it. You can benefit by signing up other users, but this is not a very often used feature. It's not an MLM site, but a subscription chess service. We track signups by ip and by browser cookies, so we're reasonable sure these are distinct people. Since we switched to the freemium model, there is little incentive for people to make duplicate accounts now, so I was hoping to see activation go up. We do domainkeys and SPF and I have gone around the block with hotmail two times already. We send approximately 25k emails a month, the bulk of which are sending out confirmation emails to people that signed up, and then a thank you for those that confirm. The rest are forgot password emails and invites.