Storefront blocks: For You & Best Sellers

Most QSortby collections need no theme work: the app writes the order back to Shopify and your theme renders it like any other collection. Two feeds are different, because there’s nothing to write back — they’re assembled at request time and rendered by a QSortby block you place in the theme editor.

• For You — a different order per visitor, driven by a Personalize collection.
• Best Sellers — one shop-wide order over a sales window you set on the block itself.

Adding a block

Theme editor → add a section → pick the QSortby block. Both live in the same place and share most of their settings.

For the For You block, the one setting that matters most is the collection it points at. The dropdown lists every collection in your shop, but the block only fetches a personalized feed when the collection you pick is a Personalize collection. Leave it blank and the block falls back to your shop-wide For You settings.

The Best Sellers block needs no collection: set Window (days) and Total products and it ranks your catalogue directly.

Three things a block can do when something’s off

Worth knowing, because the three look different on the storefront and mean different things:

Shop-wide For You is switched off. The block renders nothing and clears its placeholder. Turn For You back on in Settings.

The collection no longer exists. The block shows a message aimed at you, not shoppers: “The collection set on this block doesn’t exist anymore. Pick another in the theme editor.” This happens when a collection is deleted in Shopify after the block was configured — the block keeps the old handle until you change it.

The collection isn’t a Personalize collection. This one is deliberately not treated as an error. If you’ve pointed the block at one of your theme’s product snippets, it renders that collection’s own product order instead — so shoppers still see products, just not personalized ones. Without a snippet configured the block clears silently rather than showing an empty state, because there’s nothing wrong with the collection, only with the block pointing at it.

Pagination and the per-visitor cache

The feed is paginated on the server. The block asks for one page at a time and QSortby ranks the whole list once, caches it for that visitor, and slices to the page asked for — so Prev/Next and infinite scroll are near-instant instead of re-running the ranker.

Two settings control the shape of that:

• Products per page — how many cards are visible at once.
• Pagination mode — numbered Prev/Next controls, or infinite scroll that loads the next page as the shopper nears the bottom.

And two separate caches control the freshness:

• Refresh interval on the collection — how long a single visitor’s ranked list is reused before QSortby recomputes it. 1 hour by default, tunable from 1 to 24. Up to 100 products are held per visitor.
• Cache TTL (minutes) on the block — how long the visitor’s own browser reuses the previous render on reload before asking again. Default 5 minutes; 0 always fetches.

The cache is keyed per shopper, per collection and per cart, so a shopper who adds something to their cart gets a fresh ranking straight away rather than waiting out the interval.

Per-collection settings worth knowing

A Personalize collection carries its own copy of the knobs the feed uses, so two feeds in the same shop can behave differently:

• Default limit — how many products a visitor sees.
• Emotional suggest — the on/off for the emotional layer on this feed.
• Refresh interval (hours) — as above.
• Repeat purchase / Return rate / Session windows — how far back the matching signals look.
• Hide poorly rated products, with a star threshold and a minimum review count.
• Low-inventory threshold — soft-suppress products running short on stock.
• Family — restrict the feed to one category.

Products you’ve excluded shop-wide in Settings are dropped from every feed before it’s cached, so an exclusion never sits inside a cached list waiting to expire.

Appearance

Both blocks share the same layout vocabulary: columns and gap per breakpoint, padding and margin per breakpoint, heading text, alignment, colour, weight and size per breakpoint, and an optional container class so the block picks up your theme’s own width wrapper (page-width on Dawn, container on many others).

For cards that match your storefront exactly, point the block at one of your theme’s own product snippets instead of using QSortby’s card markup — the same App cards vs Theme cards choice the upsell widgets offer.