I can give you my views of "gamification" of online philanthropic work (on any website or for any online organization / company).
Knowing "points" primarily helps an individual set goals for themselves, not in competition with others. Points are like milemarkers on a road or highway:: they help you to know how far you've gone so far. However, in Tomnod, we are never told the total "miles" (number of tiles) from start to finish, so knowing your own "points" for a campaign does little except keep you motivated to "run another 100 steps". Without number of tiles, points do little else.
Competitions in Tomnod can be frustrating, unlike on other websites (such as a Q&A website competition). (We only had a couple posted in the forum.) There is not the spread of "levels" to accommodate the various levels of involvement. On a Q&A website, the company there might set 4 levels-- top prize of 1,000 answers, with 10 winner spots available; 500 answers with 10 spots available; 150 answers with 15 available; and 25 random prizes for anyone who just signed up and answered 1 question. That spread of available prizes takes into account the energy levels of different ages and attempts to reward at various points of participation.
"Rules of play" is not really applicable on Tomnod (nor other philanthropic work on other websites). Negatively to Nodders (in my opinion), we are often not given enough "rules". We often struggle to "figure it out" when most of us have no prior education in this work. However, this "looseness" of "rules" is present on many volunteer 'worker' websites. The loose guidelines give ordinary people the right to do what we think needs done within the guidelines those companies use. But in particular with Tomnod, people seek more rules, more guidance, more substance to know if what we are doing is correct. That uncertainty is harder to get over for Nodders; it takes us longer to throw caution to the wind and make up our own rules when faced with rule-uncertainty or new-situation-uncertainty.
While little of gamification seems to apply with crowdsourcing in particular, all online volunteers want some evidence that our philanthropic work is doing "something good", especially for Tomnod's humanitarian causes. However, that communication is often non-existent. We hear nothing and this is often a big complaint. Secondly, in absence of gamification strategies---and especially with the absence of any / all other feedback--- some form of recognition needs employed. IMO, recognition/reward must be used to promote continued participation. Recognition types, such as: (1) Communication of "How we're doing" / How we've helped (2) Paper Certificate of Participation each year (3) Paper or Digital Notes of Appreciation (4) Small Prizes (5) Small yearly "gifts" (6) Special Awards (7) digital badges for top contributors and ALL contributors; etc.
While all Nodders have their own reasons for being here, these are my observations based on my time here and in volunteering for other websites // companies. You can contact me by Private Message if you want me to participate any further in your study or if you need any other information.
Nodder and Tomnod Moderator