It wouldn't matter if the lemming effect existed on some silly poll. However, many regions will use the poll feature for 'serious' topics such as elections. Current examples:
- Local Council Election - the South Pacific
- Delegate Election - South Pacific
- RP Head - West Europeia
- Some sort of amendment - The Democratic Sphere
- Etc
This boosts on-site activity and is convenient. But the lemming effect is certainly likely to be prevalent.
I suggest that polls have the option to hide results until the end. This way, it would be impossible for the lemming effect to exist, simply because there is no majority to vote with. It's an elegant and hopefully-easy solution to a notable issue with polls.