Brazilian sellers can't get warehouse dates, so a 57KB extension keeps refreshing for them

FindFull is a Chrome extension for Brazilian Mercado Livre sellers that does one thing: refreshes the Full "inbound booking" page for you, and selects and confirms the date the moment it opens. It launched in Sep 22, two e-commerce creators pushed it with discount-code Reels, and it reached 2,000 users in under three weeks, at the highest price in its category. It was built with early creator distribution, and the product itself has no moat: eight or nine clones appeared within one peak season.

Oct 3

2026 Oct 3: Brazilian e-commerce teaching account @market.facil posted two Reels on Instagram.

The first asked a question sellers in group chats ask every day: "Is it a bug that Full has no pickup dates?" It answered itself: "It's a bit of everything, but it's not a bug. Before Black Friday logistics clog first, and Full gets hit hardest. Dates will only keep shrinking. October and November will be worse, so prepare early." The most-liked comment: "No weekend dates for over five years."

The second was co-posted with @findfullbr: "Full shipments have no dates? FindFull books them for you. Comment FULL and I'll DM you the link and discount code MARKETFACIL20."

Two days later, Oct 5, FindFull's Chrome Web Store user count went from 0 to 608 (third-party extension stats, 10-05).

What it is

Mercado Livre's Full is its official fulfillment service: sellers ship their stock to Mercado Livre's warehouses, and the platform handles delivery. Before sending goods in, you have to book an inbound slot in the seller backend. Slots get snapped up fast. When peak season starts, the page shows nothing bookable, so sellers can only refresh every so often and hope. On Reclame Aqui, Brazil's complaint site, a string of complaints turns up with titles like "No dates, can't book a Full pickup" and "Can't schedule Full shipping because there are no dates." In 2025 October, the same thing happened: a wave of "Full booking is impossible again" and "Full is a mess every year-end" videos on Instagram and TikTok. This pain comes back every year.

FindFull took over the refreshing. The store listing says it plainly:

1. Open a Full's "schedule shipping date" page, one tab per Full;
2. Enter the date you want, rank several days by priority or give a range; choose pickup or self-delivery, and for self-delivery pick a warehouse and time slot;
3. Click "start search". The extension refreshes the page and reads the calendar at your chosen interval (30 seconds to 5 minutes), selects and confirms the date once it appears, checks that it actually saved, then sends a Windows notification, a sound, and an email.

Two more details are for big sellers shipping several batches a week: if several Fulls are set to the same range, they automatically spread across different days; and once a date is booked, you can keep the task running and it will switch to a higher-priority date if one opens.

The whole package is 57KB, version 2.6.0, updated Oct 23 (Chrome Web Store, 11-06). The developer is registered as an individual in Sorocaba, São Paulo state. The old website linked from the store page sits on a Cloudflare Workers subdomain named pedrovitorrbeirosilva and now redirects to findfull.com.br.

Where the money comes from

The store charges nothing; payment happens on the website. After installing, you log in with the email used at subscription and receive a 6-digit verification code before you can use it.

Payment runs through Mercado Pago. Annual plans can be paid by Pix, boleto or credit card in 12 installments, with a full refund within 7 days. The team plan is annual only, paid upfront, with no auto-renewal.

The landing page doesn't compare prices. It shows a calculator: "how many orders per day on Full × average order value × days your stock sits waiting for a slot = how much you're losing." The big line above it reads: "Without a slot on your Full, how much are you probably losing right now?" The pricing section is titled "Cheaper than one missed slot." For a seller shipping dozens of orders a day, R$50 a month is roughly the gross profit on one order, so the math is easy.

How many paying users there are isn't visible from outside. 2,000 is the install count, not the subscription count. At a 5% to 15% conversion rate, monthly revenue lands between R$5,000 and R$15,000 (estimate, about $900 to $2,700).

Where users come from

Almost all of it came from Reels on two e-commerce Instagram accounts, co-posted with @findfullbr, each with its own 8% discount code:

The user growth curve matches this timeline. 10-03 posted first, 10-05 608. 10-09 posted from the second account, and 10-08 to 10-21 users climbed from 920 to 2,000 (per third-party plugin stats). After that it stayed flat at 2,000,11-01 to 11-06 users a day (Chrome Web Store, 11-06).

The product's usage guide has a "I have a discount code" field, and the codes are built into the product. That strongly suggests an affiliate program paying commission per code (inferred). I couldn't find the commission rate or the follower counts for the two accounts. FindFull's own IG bio says "the first Full booking plan." I found no content on TikTok, YouTube, or X, and no sign it has run paid ads.

What users say

The store shows 6 ratings, all 5 stars, which is too small a sample to mean much. The real feedback is in the comments under the Reels:

• Under the @market.facil post: "Still haven't received the verification code!"
• Under the @oliveiraecomm post: "We subscribed, but it didn't work the way we expected. We've sent 3 emails asking to cancel and nobody replied! Emails we sent before subscribing went unanswered too."
• Another person under the same post: "I re-subscribed, it asked for a verification code, and I've already DMed them."

A one-person product suddenly took on two thousand users, and customer support and login verification codes were the first things to break. That's its most obvious weakness.

Who it's competing with

There's no technical barrier: scheduled refreshes, reading the page, clicking the button. One season brought a whole cluster of copycats (Chrome Web Store user counts, 11-06):

Mercado Livre's official booking page only lets you pick dates by hand. There's no waitlist and no auto-grab. Their official advice is "don't cancel last minute, so more slots open up for everyone."

FindFull has about 20 times the users of the number-two product, yet it's the most expensive and has no free trial. Its lead comes from two things nobody else did: it launched in Sep 22, ahead of the season, and by Oct 3 creators were pushing it with codes. Most competitors only appeared on Instagram in mid-to-late October.

Where it goes from here

Black Friday falls on Nov 27, then Christmas. That month and a half is its best window. Once inbound volume eases, it's unclear whether anyone will keep paying R$49.90 a month. Annual subscribers have already paid for the year. Monthly subscribers may cancel heavily in January (inferred).

Two more risks: if Mercado Livre changes its booking page, the plugin has to be rebuilt. And if the platform ever restricts automated refreshing, the whole category goes down with it.

If it were you

The verdict: Don't build another Full slot-grabbing plugin for Mercado Livre Brazil. Eight or nine entrants crowded in within one season, some free and some at half price, and only about three weeks of peak season are left. The model is what's worth taking: find booking scenarios where the platform only allows manual refreshing and demand peaks on a fixed schedule. Launch before the peak, cold-start through vertical creators with dedicated codes, and let the landing page show the cost of losing a slot instead of a price comparison.

Who it suits: people who can write browser extensions and already work in e-commerce, or know a platform's seller community. Also people who can accept that only one or two months a year are truly profitable.

Who it doesn't suit: anyone who wants a product with steady year-round subscriptions. Anyone coding solo with no time to answer support emails (FindFull's bad reviews all come from this). Anyone who can't handle the work stopping every time the platform changes a page.

How to do it: first confirm the pain is real. Candidates: Mercado Libre's Full in Mexico, Argentina, and Colombia (same company, same fulfillment network; check in local seller groups whether slots are also unavailable at peak). Shopee Brazil's warehouse inbound booking. Amazon FBA inbound appointments across marketplaces. Once the pain is confirmed, copy FindFull's feature set: parallel orders, priority ranking, hold-then-swap, post-confirm verification, multi-channel alerts. Email verification codes are fine for login, but someone needs to watch the inbox, and a WhatsApp support line helps. On price, copy its model: monthly and annual plans side by side, with a team tier sold as annual, paid up front only.

How to get users: find two or three teaching accounts in this platform's seller niche. Give each a 8% dedicated code paid on conversions, co-post Reels with your official account, and collect leads with "comment a keyword, get the link by DM." Put a loss calculator on the landing page, not a price comparison table.

When to launch: ship 2 to 4 weeks before the target platform's peak season. Latin America's peaks are Black Friday and Christmas. This year it's already too late; the next window is to be live before the end of September 2027. If the platform you pick has another holiday peak (such as a mid-year sale), work backward from that instead.

Signs you've misread the market: (1) you ask around local seller groups and nobody says slots are unavailable; (2) a week after creators post about you, you've gained only a few hundred users; (3) a month after peak season ends, monthly subscribers have dropped by more than half, meaning the demand was a one-time seasonal spike that can't support a subscription; (4) looking back at FindFull, its user count falls clearly in February next year, which is the same signal.