Take a look at bitcoadz.io. Looks better than other networks. Minimum amount for payment is Ƀ 0.00100000, so you could give it a try for a few days.
I checked them, almost all of their ads are published on faucets websites. This is noot good traffic.
Your instructions are very precise, but advertising is only limited to 7 to 8 days, if the OP only requires the duration as specified I think this is trustworthy ad space
Well, apart from direct ads on bitcointalk which are legal but limited in time, there are also signature campaigns that do a similar thing but pretty much forever.
Op, take a look at this section of the forum:
https://bitcointalk.org/index.php?board=52.0. You can find some examples of signature campaigns there. A signature is what you can see, for instance, under my post. When you start a signature campaign, you recruit members of this forum to wear this kind of signature (and avatar) that can have the name, short info and the link to additional data on the book you want to advertise. You cannot expect the people you hire to actually write posts about your book, but its name will be behind every post they make, so it might be not a bad type of adversiting.