I always imagine that these services are supposed to serve as the &quot;automation put me out of a job&quot; of the full-time personal assistants had by the wealthy.<p>In that role, it&#x27;s usually the assistant&#x27;s job to present a selection that&#x27;s sorted by <i>optimality</i> on axes of both quality and price (and arrival time, reliability, packaging options, etc.) Properly done, this means that you should almost always be &quot;defaulting&quot; to the first option presented; rarely switching to the second or third (and there only really needs to be two or three) when there&#x27;s something in particular that stands out about them despite them optimizing lower.<p>When described this way, it&#x27;s clear that this is a much harder job than just doing fancy language recognition. An AI personal assistant has to know what you <i>care about</i>—what weights you put on various optimization criteria—without you having to explicitly specify them. Presumably it would be an online learning system, and screw up a bit at first.<p>I think the key in such systems is how they&#x27;d behave <i>before</i> being trained by lots of individual preference data over time, though. Hopefully it could &quot;guess&quot; at some initial preferences in a good way. (Maybe by taking all the preferences of every other user, putting your sparse preference-set as a point in that preference space, and then seeing how you cluster: effectively &quot;stereotyping&quot; you based on its other &quot;employers.&quot;)<p>On another tangent, one thing I haven&#x27;t seen built into any such system yet is the &quot;active academy model&quot; mentioned here (<a href="https:&#x2F;&#x2F;scifiinterfaces.wordpress.com&#x2F;2014&#x2F;06&#x2F;24&#x2F;course-optimal&#x2F;" rel="nofollow">https:&#x2F;&#x2F;scifiinterfaces.wordpress.com&#x2F;2014&#x2F;06&#x2F;24&#x2F;course-opti...</a>). One of the criteria you&#x27;d expect a PA to optimize for in their employer is <i>patience</i>. Rather than staying with an initial optimization-problem solution, if the answer is not time-sensitive, one can continue to search the solution-space for new, better solutions that might crop up (involving things that maybe didn&#x27;t even exist at the time the question was first asked.) If given two weeks to book a hotel room, there might be a good hotel room on the market <i>now</i>, but a better one on the market <i>later</i>. There are very complex questions involving the costs of reserving and then cancelling reservations to re-book, or holding off on reserving and maybe never finding anything better and running out of time.<p>For physical goods, there is even the possibility of an &quot;indefinite optimization problem&quot;—if I tell my PA to &quot;buy me a top-of-the-line computer&quot;, then presumably I want my computer to <i>continue</i> being top-of-the-line unless otherwise noted, and this will require constant weighings of various components&#x27; or configurations&#x27; depreciation-rate, market-liquidity, employer&#x27;s opportunity-cost for maintenance time, etc. All the questions a major corporate IT &quot;buyer&quot; employee considers, behind the facade of a single innocent request.