An "11.5% conversion rate" is a bit disingenuous. Their advertisement method attracted users who were not "actually eligible to even think about becoming a pay

An "11.5% conversion rate" is a bit disingenuous. Their advertisement method attracted users who were not "actually eligible to even think about becoming a paying customer". I don't think you can so easily exclude them. Put them back in and you have "over 1,000 free accounts" and only 53 that upgraded. Assuming "over 1,000" means "over 1,060" then 53 paying accounts actually means "less than 5%" which fits with their assertion that "the average B2B conversion rate is around 3-5%". While I applaud converting 461 "potential paying customers" into 53 paying customers, the 11.5% rate seems more like an internal metric. It's important to focus on what you can achieve and so segmenting out those with the requisite "subscription revenue" to be able to convert is useful for refining internal goals, but there is a reason why the average conversion is so low: you always get customers who can't pay. If other businesses were excluding those customers the quoted average would be greater than 3-5%.