An advertiser is asking questions about where traffic is coming from (I cloak the referral string via a HTTPS redirect) and why the conversion rate is so damn good (it's a strong traffic source), but I'd rather not reveal what I'm up to (most advertisers wouldn't like it, even though it's not evil). Any suggestions for a plausible response? Was thinking of; "I buy PPC search traffic and run users through my own tracking solution for ROI monitoring and quality assurance. This process strips the referral URL. I'd prefer not to reveal my KWs as its proprietary information. I pre-qualify clicks through optimsed ad copy, but more data is still needed to see an accurate representation of the conversion rate".