I never noticed any timeshare sales people in Sidari, but on the Spanish islands it's a nightmare.
They come up to you with scratch cards and push them onto you. Everyone's a winner and once you've won whatever it is, they want to take you to some remote part of the island so that you can claim your prize.
Once they have got you, all they want to do is pressure you in to signing up for something you wouldn't have thought about signing up for.
You do usually get some sort of prize for going with them, but is it worth taking a day out of your holiday to go with them and can you resist the pressure sales ?
Anyway hope they never get into that sort of thing in Corfu.