what do you think of using blog social share rewards? worth it?

something along these lines, since i use wordpress anyways

basically the idea is:
increase engagement, encourage repeat visits and build a loyal following on your WordPress blog. Despite the growing interest in gamification, there are really only a handful of plugins available that are stable enough to provide Wordpress site developers a viable point and reward system to their users.

then they listed 4 plugins:
Incrwd: A loyalty program plugin that uses real rewards to incentivize users to visit the site, share posts on Facebook and Twitter, and comment more often.
Achievements for BuddyPress: Built for the popular BuddyPress community platform for WordPress, this plugin helps bloggers promote and reward social interaction with challenges, badges and points. The plugin only works with BuddyPress and requires support for several other core plugins.
Punchtab: Released mid-2011, Punchtab is a loyalty program plugin enabling readers to sign in through Facebook, and earn points for activities such as visiting, commenting or sharing on Facebook, Twitter and PlusOne’s. Readers can also redeem points that site owners must first customize.
Big Door Quick Gamification: Released by gamification technology startup Big Door, this plugin enables WordPress site operators. Big Door’s point system is based on activities, earning users experience points and badges for checking in to the site.

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i was just wondering if anyone was using this to engage more out of users and if it was something i should be putting a little more research into or if anyone had some experience?