We've always said that using HTTPS for all of your website pages and not just checkout pages is a good idea. It encrypts all of the data, gives users that warm, safe feeling and marks your site out as willing to go the extra mile for them. Good marketing in other words.

 

It seems that Google will soon be taking HTTPS into account when indexing sites. They admit that HTTPS' weight in ranking sites is somewhat low at the moment; high-quality content is still the most important factor. However, the company does say that in time, it might choose to increase the effectiveness HTTPS has on ranking.