I have found it easy to recommend to non-technical people. (In the early days of Google, I had to spell it for people too... at least this is 3 common words.)
I think the emphasis on converting non-technical people is also often misplaced. Non-technical people don't care about any of the issues that lead to development. The number of people using Skype shows most people don't care about privacy. That doesn't mean DDG's offering is not unique or valuable, it's just that the people to recognize that value will not be the majority by any stretch - but, it never is - and converting people who have the hardest time understanding that value should be a low priority IMHO.
In promoting privacy, DDG captures the union of early adopters, technically literate, and digital evangelists - all groups that are most likely to understand as well as turn around and effectively promote it (for example, by setting the homepage and default search engine after cleaning up a system for a friend)... This is the crowd to keep happy (without raising the barrier to entry either... for example, late adopters will not use bangs or care that you search Hacker News too, but the early adopters appreciate it greatly). These were the same types of people promoting the early Internet to the masses, who barely saw the point in having a computer.
In that vein, one of the best things for DDG, IMHO, would be to make setting ALL browsers as easy as possible (homepage+default search). (I know I'm not saying anything new...) There are add-ons for individual browsers, for example (which I tend not to use, because I like vanilla installations without extensions to upgrade later), and conventional methods (which I prefer, but have been de-emphasized in favor of add-ons), but further-centralizing the process of applying these customizations would be nice. For example, I'd rather download a single native app or portable script (WSH) that was capable of searching out browsers and - through check-boxes - setting their homepage and search (ideally to the SSL search), via the browser-native method (or add-on method), in one pass (usable offline, and ideally at an easy-to-type URL like "duckduckgo.com/tools"). This would help high-turn-over scenarios like tech-support shops, which has the chance to affect the most users but are also under pressure, so want to do the minimum possible (Idea: actively promote to these places).
On a different note, I'm curious how the costs associated with this XMPP service are expected to grow and how it is seen from the business side. If 100000 people started to use it for messaging, would it become too burdensome and be discontinued, or is there a plan for cost-recovery (or is the ddg bot enough of a case)?