Automated builds and charges

Something I do need to think about should webmentions take off on my site. — I can get the site to rebuild every time it’s mentioned on Twitter, micro.blog etc., but Netlify only offers 300 free build minutes a month. Each deployment takes around a minute, while the actual build is 6-7s. I’m not sure which period Netlify uses to calculate build minutes, but if it’s time to deploy, it could soon start costing.