Thumper, I have to agree with you! Being polite and genuinely friendly works wonders. Even if I don't get an upgrade I find the whole flying experience to be so much more fun.
Attitude is so important! One person I regularly travel with gets grumpy and out of sorts and even angry with every little problem. I tend to see it all as a challenge and know that things will go wrong. Gosh, which one of us do you think actually makes friends on the road? And I'm talking the kind of friends who will actually keep in touch and help one another out when visiting their home towns.
Hope I didn't veer too far off the topic.
<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by Thumper:
Interesting that some respondants tried to offer help and some offered their view that it is possible to benefit from being nice.
It is even more interesting that the more sarcastic the responder, the less likely they thought it was to get an upgrade for being nice to others.
Sorta sums up my argument nicely 
Keep snarling all, maybe I'll send a drink back to you in the main cabin next time we meet. </font>