Indie publisher here. Nice job - it came out quite well, judging by the images. Curious if the editor and proofreader were working with the same software, or it had to be exported to markdown or some other format.
Facebook ads are not a good investment, IMHO. They are expensive, campaigns take time to set up, and most people on FB are not on the site to browse books. Amazon Advertising is more effective and will be available to Amazon KDP users.
A note about ISBNs: You don't need one if you are just publishing a PDF on Gumroad or an ebook on KDP. If you are creating a print edition through KDP or a service like IngramSpark, you will need an ISBN, though.
For authors based in the states, a warning: The U.S. ISBN registry, Bowker, is a monopoly and prices accordingly so if you do want to go that route the outlay will be significant: $125 for a single ISBN in the registry and $250 for 10 (the last time I checked). Bowker will try to upsell overpriced and unnecessary services, like $25 barcodes and copyright assistance for $80 a pop not including Copyright Office fees. Bowker also left the barn door open on its CC page for six months earlier this year (https://www.publishersweekly.com/pw/by-topic/industry-news/b...).
Facebook ads are not a good investment, IMHO. They are expensive, campaigns take time to set up, and most people on FB are not on the site to browse books. Amazon Advertising is more effective and will be available to Amazon KDP users.
A note about ISBNs: You don't need one if you are just publishing a PDF on Gumroad or an ebook on KDP. If you are creating a print edition through KDP or a service like IngramSpark, you will need an ISBN, though.
For authors based in the states, a warning: The U.S. ISBN registry, Bowker, is a monopoly and prices accordingly so if you do want to go that route the outlay will be significant: $125 for a single ISBN in the registry and $250 for 10 (the last time I checked). Bowker will try to upsell overpriced and unnecessary services, like $25 barcodes and copyright assistance for $80 a pop not including Copyright Office fees. Bowker also left the barn door open on its CC page for six months earlier this year (https://www.publishersweekly.com/pw/by-topic/industry-news/b...).