If you're not using McAfee's free "SECURE" trust mark app, stop reading this and install it.
(I was going to say "...it takes just moments", but that's the issue that prompted this post, so more on that in a moment).
If you are new to ecommerce - or selling online in general - there is plenty of documentation attesting to the benefits of trust marks, trust badges, etc. (see this Crazy Egg article for a good overview).
If you're building or running a Shopify store, the only possible rationale not to leverage the benefits of trust marks - cost - dissolves; McAfee offers an easy-to-install trust badge through their free app.
So what about that second paragraph, and the "props for support" in the thread title?
Knowing clearly the benefits, I decided to upgrade from the free app to McAfee's reasonably-priced 'Pro' version; it removes the 500-impression limit on the free app, and includes the very-worthwhile option to add additional trust marks arbitrarily throughout your store, like next to the 'Checkout' button, where it has it's strongest and most effective impact.
Unfortunately, it didn't go as smoothly for me as the inital app install did. I paid my money, and... nothing. Not only didn't it upgrade, but I could no longer get into the app's configuration dashboard.
After maybe a half-hour of dickering around, I clicked on McAfee's support link and created a support ticket.
Then I left it alone. Honestly, I wasn't expecting much - most likely, a generic "tier-1 tech support" reply that wouild be neither helpful, or timely.
To my happy surprise, I received a very prompt, personalized reply from a real person ("Brandon Rogers", w/ pic!); next thing I knew, the trust mark was working.
I replied to Brandon Rogers to let him know, but mostly so the support ticket would be closed.
To my even happier surprise, Brandon followed up again, with some additional and useful info that I hadn't even asked for!
And that, fellow IM'ers, is a lesson itself: that little above-and-beyond effort that this vendor took not only "secured" them (pun intended) a happy customer, but thrilled me enough to take the time to 'shout out' my experience to other potential customers.
To sum it up: you should be using a trust mark, and McAfee's free Shopify app is an excellent choice.
And treating your customers - and potential customers - well is one of the best investments you can make.
Michael Ullman