Or it fits better than you think, and/or the margins for certain types of products are high enough to justify bidding for ads even when they fit only a tiny proportion of the time.

E.g. you may have a relationship with Linode, AWS and DO, but presumably all three would prefer you ditched one or two of the others for more spend with them.

And you may have done a kitchen replacement two years ago, but how many percent need to do repairs or changes subsequently, or are unhappy about choices they've made, and end up spending enough on high margin additional products for years to come? That you've proven yourself to be willing to invest in improvements recently might well make you more profitable to advertise to even though you've already made the biggest investment.

I'm sure many advertisers are bad at targeting, and so I'm sure some of these ads are metaphorically burning money. But I'm also sure - because I've seen that too - that sometimes seemingly totally counter-intuitive ads makes sense after all with access to the actual underlying numbers.