Hamsterra vs
Hamsterra vs BookSirens
Both help authors send advance review copies. BookSirens sells promotion to its own reviewer community; Hamsterra is a free ARC workspace with paid plans for higher limits. Here is how they compare on the same 16 points we use for every product.
This comparison is published by Hamsterra. Product names belong to their respective owners. No affiliation or endorsement is implied. Spotted something out of date? Send a correction.
Side by side
“Not publicly confirmed” means we could not find it on the product’s public pages; it does not mean the feature is missing.
| Point | HamsterraFree, Stash, Hoard | BookSirensDIY, Promote, Author, Partner |
|---|---|---|
| Access and pricing | ||
| Free plan for authorsWhat an author can do without paying | Free with limits 100 readers per campaign, 100 invitation emails in any 30 days, 500 MiB of files, 1 pen name. No time limit. | Free Free for ARCs sent only to readers the author brings. No numeric limits published. Sources: BS-E01,BS-E04 |
| Introductory offerTrial, welcome credit or one-time free start | Not offered No trial: the Free plan has no end date. | Paid No free trial. What an author spends on a first Promote ARC is credited towards the Author plan. Sources: BS-E07 |
| Billing modelHow paid use is charged | Free; paid for higher limits Subscription: Stash €8 a month before VAT (UK consumers: €9.60 including 20% VAT), Hoard €15 a month before VAT (UK consumers: €18 including 20% VAT). No per-book or per-reader fees. | Paid Promote: $10 per accepted book plus $2 per recruited reader who downloads. Author: $100 a year. Sources: BS-E01,BS-E05 |
| Product accessWho can start and how | Free Open sign-up after email verification. No book approval before publishing. | Free Open sign-up; books undergo acceptance checks against published guidelines, with possible exceptions. The submission queue is 0–3 business days, followed by a file check of up to 48 hours. Sources: BS-E09,BS-E10 |
| Finding readers | ||
| Own readers and teamSending to readers the author already has | Free with limits Invitations to readers who opted in on Hamsterra, counted against the invitation limit. No import of an existing contact list. | Free Shareable invite link per book; invited readers are not billed. Sources: BS-E04,BS-E12 |
| Reader discovery on the platformReaching readers the author does not know yet | Free Published campaigns appear in the public ARC catalogue while eligible for listing. No paid promotion. | Paid Catalogue, genre newsletter and group promos. According to booksirens.com, 51,000+ reviewers. Sources: BS-E01,BS-E14 |
| Private campaignA campaign not shown publicly | Not offered No private, link-only or invite-only campaign setting. | Free A private ARC is not promoted; the author shares the listing link. Sources: BS-E04 |
| Reader approvalWho decides which readers get a copy | Free The author approves or declines each application, manually or automatically, with an optional form. | Free The author can approve or decline each request, including from invited readers. Sources: BS-E20,BS-E02,BS-E03 |
| Delivery and results | ||
| Reader recordsContacts, history and export | Free with limits Contacts with consent history and tags; CSV export of eligible contacts who opted into the author’s reader list; blocked readers. No contact import or notes. | Not publicly confirmed Per-book activity feed, blocking and a subscriber CSV exist; which plans include them is not stated. Sources: BS-E15,BS-E17,BS-E19 |
| Delivery formatsHow readers receive the book | Free EPUB and PDF download. No browser reading, no Send to Kindle, no audiobooks. | Free EPUB and PDF. Readers choose Send to Kindle, email attachment or download; upload up to 100 MB. Sources: BS-E18,BS-E22 |
| Review trackingHow reviews are followed up | Free Readers add up to 10 review links; reminder rules. Self-reported, not checked on review sites. | Free Reminders and review tracking for the author’s own readers; how reviews on other sites are detected is not stated. Sources: BS-E02,BS-E23,BS-E24 |
| Private feedbackFeedback only the author sees | Free Up to 5,000 characters with any result. | Not publicly confirmed Did-not-finish reasons are shared with the author; a general private-feedback form is not publicly confirmed. Sources: BS-E27 |
| Growing a list | ||
| Reader magnetsFree books for list sign-ups | Free with limits 1 open magnet on Free; 5 or 20 on paid plans. | Not publicly confirmed Readers can join the author’s list after a review; standalone magnets not described. Sources: BS-E17,BS-E28 |
| Group giveawaysSeveral authors sharing one giveaway | Free with limits 5 giveaways at a time on Free; on paid plans the limit follows the giveaway rating. | Not publicly confirmed Group promos are run by BookSirens for paid listings. Author-organised giveaways are not publicly confirmed. Sources: BS-E14 |
| Visible copy personalisationReader details printed in the copy | Free Each campaign copy shows the reader’s name and a Copy ID; a free-book copy shows the reader’s email. Not DRM. | Not publicly confirmed Watermarking is announced as in development; whether a mark is visible or shows reader details is not stated. Sources: BS-E29 |
| Campaign analyticsNumbers about visits and results | Free with limits Last 30 days on Free; 12 months, sources and CSV export on paid plans. | Not publicly confirmed An activity feed of downloads, reviews and did-not-finish exists; no report list or plan coverage is published. Sources: BS-E15,BS-E19 |
Scroll the table sideways to see both products.
Pricing and limits
BookSirens prices from its official pages; Hamsterra prices from our plans page. Both checked 29 October 2026.
Hamsterra
- Free
- €0
- Stash
- €8 a month or €80 a year before VAT. UK consumers: €9.60 a month or €96 a year, including 20% VAT
- Hoard
- €15 a month or €150 a year before VAT. UK consumers: €18 a month or €180 a year, including 20% VAT
- Readers per campaign
- 100 / 1,000 / 4,000
- Invitation emails in any 30 days
- 100 / 1,000 / 4,000
- Book and promo files
- 500 MiB / 5 GiB / 20 GiB
- Open reader magnets
- 1 / 5 / 20
- Pen names
- 1 / 2 / 5
Prices before VAT; VAT is added at checkout. See plans.
Other features
Hamsterra
- Street team campaigns next to ARC campaigns · Free
- Copy check: match a Copy ID to an issued copy; marks can be removed or lost · Free
- Public author and book pages with page designs · Free with limits
- Blocked readers list with import · Free
When each one fits
Hamsterra may fit if you
- want ARCs, magnets and group giveaways in one free workspace
- want readers to see their name in each copy
- want higher workspace limits for a flat subscription
BookSirens may fit if you
- want to pay to reach an existing reviewer community
- want Send to Kindle delivery
- need a private ARC that is never listed
Key differences
- BookSirens charges for recruiting readers; Hamsterra lists every campaign publicly at no charge.
- BookSirens supports private, unlisted ARCs; Hamsterra has no private or invite-only campaign setting.
- BookSirens delivers to Kindle and email; Hamsterra delivers EPUB and PDF downloads.
- Hamsterra includes reader magnets and multi-author giveaways; BookSirens group promos are run by BookSirens.
Questions
Is BookSirens free?
Sending ARCs to readers you bring yourself is free. Promotion to BookSirens reviewers is paid per book and per reader, or with the yearly Author plan.
Does Hamsterra charge per reader?
No. Hamsterra has no per-book or per-reader fees; paid plans raise limits such as readers per campaign and storage.
How often is this page checked?
Our target review interval is 30 days for prices and 90 days for other points. The dates of the last check are at the top of the page.
Sources
- BS-E01 · Pricing Plans · checked 29 Oct 2026
- BS-E02 · How does BookSirens work to help me get reviews? · checked 29 Oct 2026
- BS-E03 · The DIY Plan is free. How good can it be? · checked 29 Oct 2026
- BS-E04 · What is the difference between a public and private ARC? · checked 29 Oct 2026
- BS-E05 · When am I billed? · checked 29 Oct 2026
- BS-E07 · Can I try out BookSirens before committing to the Author Plan? · checked 29 Oct 2026
- BS-E09 · What is the acceptance criteria? · checked 29 Oct 2026
- BS-E10 · What is the submission process? · checked 29 Oct 2026
- BS-E12 · Can I invite readers to download my book on BookSirens? · checked 29 Oct 2026
- BS-E14 · Reach Influential Book Reviewers · checked 29 Oct 2026
- BS-E15 · Do I get to know who all downloaded and reviewed my book? · checked 29 Oct 2026
- BS-E16 · Can I transition my ARC readers from another site to BookSirens? · checked 29 Oct 2026
- BS-E17 · How can I get the email addresses of readers who have opted into my mailing list? · checked 29 Oct 2026
- BS-E18 · How do readers receive my ARC? · checked 29 Oct 2026
- BS-E19 · My Readers (category) · checked 29 Oct 2026
- BS-E20 · Can I vet readers before they access my ARC? · checked 29 Oct 2026
- BS-E22 · My book's file size is too big. How do I upload it? · checked 29 Oct 2026
- BS-E23 · Where are the reviews posted? · checked 29 Oct 2026
- BS-E24 · When are review reminders sent out? · checked 29 Oct 2026
- BS-E27 · Do I get to know why a reader decided not to leave a review? · checked 29 Oct 2026
- BS-E28 · Grow Your ARC Team · checked 29 Oct 2026
- BS-E29 · How do you guard against piracy? · checked 29 Oct 2026
- BS-E30 · Book reviewer directory · checked 29 Oct 2026
- BS-E31 · My Listings (category) · checked 29 Oct 2026