These results are very biased by the early-adopters that frequent hackernews. There are WAY more people out there are using the recurring functionality of the

These results are very biased by the early-adopters that frequent hackernews. There are WAY more people out there are using the recurring functionality of the gateways (ex. Auth.net, Braintree, Linkpoint / First Data Global Gateway) than one of the standalone recurring billing systems (recurly, chargify, etc). However using those legacy solutions is a SHAME because they are in general quite horrible. They are certainly cheaper, and may seem like the path of least resistance, but they don't do the job well enough for serious companies. You want something like Recurly, Chargify, Zuora, CheddarGetter, if you are doing either recurring or metered charging of your customers. It will make your life easier and is worth the expense.