netmeg - 5:53 pm on Feb 25, 2013 (gmt 0)
Well it depends on what kind of site it is. For my own event sites, I maintain a privacy and disclosure policy, a republishing policy, and some method of contact - be it email address or a contact form. I'm not selling anything on those sites, and they're all pretty well marked with my extensive and unique (cough cough) social footprint, and it doesn't seem to have been an issue so far.
For my ecommerce clients - most of my clients are B2B in old and established niches, and the toll free number does seem to make a difference (we've tested it) My biggest client has a call center in order to offer 24/7 phone orders and customer service, and so far none of his competition (apart from the super huge players like Amazon) do that - that gets used quite a bit.
I think the ecommerce security signals do make a difference, particularly on sites that deal with banking or financial niches.
I believe strongly in a robust About Us page for professional organizations or ecommerce, with physical addresses, staff and management names, pictures, and as much specific information as possible. For Google purposes, tying to a local business profile (Google+) probably means something (not to users so much, but to Google)
I try and put revolving testimonials on site if I have them. And I mean testimonials about the company, not just the products.
I was recently contacted for consulting by a company that was offering ... not exactly medical advice, but something just bordering on the edge of it. The first thing I noticed was that there were NO professional credentials on the site whatsoever. In other words, there was no reason for me to believe these people knew what they were talking about. If you're in a field like that - or basically any field where you're setting yourself up as some kind of expert or authority, you better say WHY you're an expert, and hopefully provide some kind of third party confirmation to back it up. Things like certifications, awards, membership in industry organizations.
I'm sure there are more, have to think about it.