I rarely upvote because doing so on HN automatically adds that article to your Saved section. I prefer to keep this section only for submissions to which I'd want to come back later (and I'm unsure if the "upvote to save" behavior can be changed).
Either way, view this as a great lesson in why getting conversions can be so tough. A person better have a very persuasive case for a stranger to go out of their way and click a button.
I'm in the same boat : Just because I like an article doesn't mean I want it saved to my permanent list. I would be very interested if there is a way to change this behavior as I would then upvote far more articles.
The saved section makes me more selective in terms of what merits an upvote. I will confess/admit/proclaim that the position of an article within the stack also influences my upvoting. In other words, my standard for upvoting is lower on the New page than the front page.
Either way, view this as a great lesson in why getting conversions can be so tough. A person better have a very persuasive case for a stranger to go out of their way and click a button.