If the lambdas are always hot, what is the advantage over having a server? I thought the big selling point of serverless was not having to pay for long stretches of time where you don't have any requests.

If you have 10m requests uniformly distributed, then yes it’s less of a problem, but that’s unlikely. (Even then lambda containers will be recycled multiple times throughout the day, so there is still a small penalty.)

I built an azure function that runs for free that just pings my .NET MVC pages periodically so they are always hot on my cheap hosting.

You can just use application insights for this. It can also show you the results of the ping over time in a scatter chart.

Oh interesting, maybe I should look into this more, I feel like it would be useful, but one day it just showed up in my projects and spammed out and drowned all my debugs in the log so now I rip it out as soon as I can because it drives me nuts and I couldn't find an easy way to turn down the messaging.

If you're still reading this, you can disable Application Insights during debugging (why would you need it anyway during debugging). To do this you make an application variable like 'EnableApplicationInsights' in your web.config so you can set per environment whether or not it should be on.

Then if this is false, in your Application_Start() you can set this: TelemetryConfiguration.Active.DisableTelemetry = true;

I need to include this into my builds.