I've recently been on the search for some good books from Amazon and I've been taking advantage of the free samples available and several well-reviewed books lost my sale because of their front matter. If your "book" is 80 pages and the sample is 10%, that gives me eight pages to decide if your book is what I'm looking for. When 6 of those 8 pages are filled with front matter (title page, copyright information, dedications, acknowledgements, a 2-page foreword, and a list of your other work), I'm going to get annoyed. Don't spend your eight pages trying to interest me in your other books. Let me get to the book I'm already interested in.
If your book is standard novel length, the sample is generally longer (since it's based on percentage) but I still don't want to turn 20 pages (I often read on my iPhone) before I get to the story. Even though I know 20 iPhone pages is more like 4 Kindle pages, it still annoys me.
As an author, I understand the extras are important, but as a reader, I say don't waste my free sample with that crap. Move it to the end of the book, or provide a clickable link to your "other work" at the beginning if you believe it's really necessary. When I read a book, I'm more likely to buy more of your books if you give me what I'm looking for. And in case you didn't know, if I have downloaded the sample of your book, I'm looking for the beginning of the book so I can determine whether to give you my money.
When I finish a book, and I've enjoyed the content and the writing style, I'm likely to look for more of your work, so include your list of work at the END of your ebook, while you have me in a happy postcoital-type bliss. If you've annoyed me before I even start reading the book, chances are high that you've lost me as a customer and reader and we'll never reach that postcoital-type bliss because you'll be shot down before the first kiss.
As both a reader and a writer, I strive to find a balance. I don't want to annoy my readers, but I do want to take advantage of the ability to share information about my other books, I'll just do it at the end of the book instead of the front.
This is just my opinion. Readers, tell me what you think about free samples on your e-reader. Authors, tell me what you think, and defend your position. I'd love to know if there's a real reason to include the three page list of other work before I get to the book.