I just got my first job in Copywriting (woot woot)!!! My client is a Financial Services Firm, and they are asking me to write curated emails for their Retail & Businesses Clients. Primarily about Investment Products and Credit Products. I was looking around on google for more information in terms of how I should quote/negotiate my rates with them. The amount of information I found is a bit overwhelming and I found 2 ways which appear to be popular in the search results, Per Hour vs. Per Words.

Would it make sense for me to charge them per hour (like $20/hour) instead of per words ($25/100 words)? Since I will be curating the contents based on the types of clients and products I am introducing them to.

Your feedback and advice are sincerely appreciated. :)