How Much Traffic Can You Get From Free Google Shopping Results VS Paid Product Listing Ads?

It varies, but here is one example :-

At any rate – while getting your products listed in the Google Shopping results is still free in the UK, if you have an e-commerce site, and you don’t already have a Google Merchant Center account set up – do it now!

PS – As far as I know there are still no concrete plans to introduce ‘paid only’ clicks on Google Shopping results in the UK – but it’s already happened in the USA – so I guess the free clicks won’t last for ever.

PPS – I still haven’t heard when Google Shopping will implemented for the Republic of Ireland. If anyone does hear about either of these things – I’d love to know. :-)