To date, I have not sold any of my novels directly from this blog, and have no intentions to do so in the near future. This means I presently have no contact information on purchasers which requires to be dealt with.
However, should that selling of novels situation change, I would comply with the GDPR conditions and would not store any personal information for longer than necessary to send out purchases of novels to any interested customers.
With regard to guest authors, or other contributors posting to my blog, I will only be storing contact information for the duration it takes to organise the information to be posted on this blog.
Should I conduct a giveaway or contest on this blog, where I require information on the winner to send on a prize, I will not store their details for any longer than necessary to organise the winning gift/ reward.