Internet Scavenger Hunts for readers are one of my favourite types of contests.
Whereas they do not generally challenge participants intellectually, they are fun and playful. Also they have an element of competition which engenders a sense of achievement at having collected all the required information. Competition is a fundamental human drive and, in my opinion, the satisfaction at having ‘won’ something through effort, no matter how minimal, is likely to be greater than if a gift is simply given away.
Giveaways have their place in anybody’s marketing arsenal, of course, and the strategy of free downloads being pursued on Kindle would indicate that this is a valid ploy. On an individual level, it seems to me, however, that it is more valid for authors with an existing backlist. For newer authors, like me, although giveaways might generate goodwill and hopefully reviews, hunts actively direct traffic to one’s site that might not otherwise visit.
Do they increase sales?
As with any marketing activity, it is difficult to quantify, but they certainly raise your profile with a potentially new audience.