For Shopify users: by default, new products and collections are made available to a new Sales Channel such as Cloudshelf. However, if your see products that are not appearing this can be because of the 2 following reasons.
Reason 1: they are not included in any collection.
Cloudshelf sources products that are part of any collection, but ignores products that are not included in any collection.
Do not leave collections blank
The solution is to either create a new collection or to include them in an existing collection.
Reason 2: they are not available to Cloudshelf
they are included in a collection but either the collection or the individual products have been made unavailable to the Cloudshelf sales channel.
Make sure Cloudshelf channel is selected
The solution is to click on 'Manage' and select the Cloudshelf channel.
If many products are not available you can use the Shopify product list page, use "select availability" to select all those that are not available to the Cloudshelf channel and group edit
Add Cloudshelf as available channel to all products