You can decide to be aggravated or amused by the hard-sell folks at the markets. We pretty much just had a good time with them or politely said "istemez," it is not needed.
I don't think I've ever met friendlier, nicer people (well maybe the Canadians). So maybe a lot of them do just want to sell you a carpet or something else but very often after we established that we didn't need what they were selling, they'd just talk with us. We talked about travel and politics, many we met were fans of the USA and especially Obama. Often we just exchanged the few words we knew in Turkish and then broke into pantomime. This young student just wanted to get a photo with us. Then we were back on the bus, friends a little longer, then farewell forever.