I could probably link to all sorts of statistics on how much conversions improve when you have one of those “trust seals” on your site. They look shiny and official, and typically you place them at the top of your footer, or sometimes in the right column. Like this:

A lot of different companies provide these, and the prices vary a lot. If your focus is on one commercial site, then it is worth the time and effort investigating which suit your needs the best. The three basic types of seal are:
- Security - your site doesn’t have anything nasty like malware, the server can’t be hacked, you have a security certificate
- Privacy – all the correct procedures are adhered to
- Trust – you are who you say you are – email, mail, phone and physical address
If you have many sites that generate small returns, some might benefit from a seal, but of course you want to get the best bang for your buck. Here’s an overview of your options:
Merchant Safe

Their key differentiator is that they are cheap. So cheap that they don’t explain the differences between their 5 seals. One is called Verified Contractor – go figure. Seems to me that the only difference is the badge. $240-$334/yr. Importantly, for $120/yr you can show the badge on multiple sites, presumably if they have the same contact details etc.
TRUSTe Starter

The product is impressive:
TRUSTe Verified Seal
Privacy Scanning
Dispute Resolution Program
Privacy Policy Generator
and so is the price, $499/yr for a meager 100 page views daily.
ValidSafe

These guys are cheap. $157/yr for their Security, Privacy or Business seals, or $297/yr for all three. Even better, the above seal is free. All it does is check your email address, but it has to be better than nothing!
SafeShops.org

The pick of the bunch (on face value, I haven’t actually tested any of these) is Safe Shops. For the first year their service is free, and from then on it is only $45/yr per seal or $60/yr for the set. Shame about the name if you aren’t a shop per se.
SiteTrust Network

These guys are real cheap ($59/yr) and have a unique selling point – user submitted feedback. Unfortunately that’s about it. They have criteria for acceptance, but nothing is verified and for all anyone knows every client is accepted regardless. However, the end user is unlikely to know or care… the shiny image is sufficient.
SiteLock

$99/yr gets you a pretty good mid-level service. For more you get daily scanning etc. If you want features without too high a cost, give them a whirl. 30-day free trial.
Business Chek

Looks dodgy, due to the style of their home page. And it seems that they do nothing more than supply the seal, and show your provided information when someone clicks on it. $77/yr but only $47/yr for Christmas!
Comodo UserTrust

It is from a top trust brand, and is free. I suggest definitely using this one and keeping it if the user reviews stay good.
Trust Guard

$197/yr gets the following verified once. Company address, email, phone, secure checkout process, and SSL certificate. Pay more to get them checked more frequently.
IBCIM.org

Not a catchy or trustworthy name. Free for 3 months, then $30/yr. No verifications, so worthless except for the eye candy.
Trustox

Only $49/yr, and gives a very good impression of the real deal. Get whichever seal you desire. Not bad, for what it is.