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Infinite scroll is fine for SEO, as long as you include code that forces a unique URL at a certain point in the scroll, to emulate a new page. Now - if you have that on category pages, and thus provide a crawlable, indexable group of pages with proper pagination best practices, you don't need that on the home page. The key though is you need at least one proper way for search bots to get to all your content through HTML links. If you don't have separate categories, and if the home page links are the only way to get to that content, then having page 2, page 3 is critical - and should not be blocked from search bots for crawling or indexing.

It seems that its still not showing sitelinks, even though the site gets somewhat significant traffic... I know the timeline for getting sitelinks can vary widely, but the site has been live for almost 6 months and no sitelinks.. is this unusual?