I noticed last time this happened too.

When switching Fibre providers I get a letter in the post from Spark saying fibre is now available along with their unsolicited offer of joining them.

I thought Spark and Chorus are sopose to be seperate now? I find it crossing the line a bit in regards to privacy - keeping tabs on peoples Internet connectivity status to send them advertising letters.

I could understand some automated letter letting me know fibre is available but to be sent it from a retailer keeping tabs on my connectivity? That I have nothing to do with.