Just got back from Cancun and last year went to Cabo.
In Cabo the vendors are persistant and are everywhere you go, on the beach and in the restteraunts. Cancun, if you go to the flee market or market 28, you will get hounded (but not on the beach) to no end by each and every vendor asking you to check out their goods, thrusting stuff at you and aggressive if you dont comply.
This becomes somewhat irritating and tireing after a while. There are no prices on anything, so each item must be haggled for if you want to buy anything, usually it is half the original price or less if you can hagggle...or looks like you are going to walk out.
But wouldnt it be so much pleasurable if they just let us browse, look and buy their junk at our own leasure instread of being hounded like a pack of dogs after a rabbit.