Each video is 30 seconds. you get 10 gold, which is worth about 3 cents.* If you were to watch 120 videos back to back in order to earn 1200 gold, you would have spent an entire hour earning $3.60. . . that is to say, you have compensated yourself at $3.60 per hour. unless you really enjoy the videos, it would be much more effective to spend that time working even at minimum wage where you would earn at a much faster rate. . . . so here are good reasons to watch videos:
1. you are actually interested in the ads
2. you need an ergo break from tanking
3. your time is worth less than half the national minimum wage (or 30% of the CA minimum wage of $12/hr).
4. you want WG content but really really really don't want to give them any money. . . for spite or whatever**
5. if you are a kid - if none of your neighbors need lawns mowed, dogs walked, or little kids looked after.
6. you are retired or otherwise on a fixed income
If none of these things are true. Do the math. earn some dollars and if you want something in wotblitz, spend those dollars on gold or tanks or whatever.
*in the basic $5 gold pack for 1500 gold, you get 3 gold per cent or 9 gold for 3 cents so I am exaggerating slightly to simplify my point. the gold/dollar amount goes up with larger purchases and the $0.99 "pocket money" is just silly.
**note that if this is your reason, you might want to determine how much you think WG gets paid for each of those ad views. I don't think it is as much as 3 cents, but it is certainly not nothing, so you are still effectively giving to WG.