Landing, 'thank you' pages and G+ avatars
Source: SEO podcast, episodes #220 and #221.
Make sure visitors can figure out what you are offering within 10 seconds after they land on your site. Or they will bounce.
Use CTA (call to action) and USP (unique selling proposition).
Look at your competitors' landing pages for best practices.
"Thank you" page
When users reached your "thank you" page they are much easier to convert because they already showed some interest.
That's a great opportunity to up-sale and engage through social media.
Make 'thank you' page a separate page so it can be tracked as a goal in Google Analytics.
At the end of 2013 Google changed algorithm of showing avatars in search results. Avatars are now shown for those who are active on their G+ accounts.