are any blogs worth paying 99 cents/month to get on Kindle? there are a bunch of them and they all seem to have a 14 day free trial period. seems like you couldn’t go wrong…
many seem to be blogs about free downloads for Kindle which makes my head hurt a little.
I am currently browsing the list of free classics for kindle on the Amazon site so I know about those. 
I don’t know anything about paid blogs - but if you’re interested in free classics in Kindle format there’s enough available from Project Gutenberg to keep you busy for a long, long time…
I think that most, if not all, of those blogs are available for free online. It’s up to you whether you think it’s worth $0.99 for the convenience of having them delivered to your Kindle. Although if you want to download the blogs’ content for free online and transfer it to your Kindle, a program like Calibre can help you with that.