That's the mistake - maybe people actually only do 9 requests per article. But the think they do a lot more. I personally think I do about 1000 spell check requ

That's the mistake - maybe people actually only do 9 requests per article. But the think they do a lot more. I personally think I do about 1000 spell check requests a month, but I don't know because it's not something I've ever thought about. So you may have very concrete data on actual usage, but have you also looked at what users think about your pricing?