All the main shopping streets, even the side streets, are touristy and overrun. The greatest concentration of shops is around Piazza San Marco and the Rialto Bridge. Prices are much higher at San Marco, but the quality of merchandise is also higher. There are two major shopping strolls in Venice.
First, from Piazza San Marco you can stroll west toward spacious Campo Morosini. You just follow one shop-lined street all the way to its end (although the name will change several times). You begin at Salizzada San Moisè, which becomes Via 22 Marzo and then Calle delle Ostreghe before it opens onto Campo Santa Maria Zobenigo. The street then narrows and changes to Calle Zaguri before widening once more into Campo San Maurizio, finally becoming Calle Piovan before reaching Campo Morosini. The only deviation from this tour is a detour down Calle Vallaressa, between San Moisè and the Grand Canal, which is one of the major shopping arteries with some of the biggest designer names in the business.
The other great shopping stroll wanders from Piazza San Marco to the Rialto in a succession of streets collectively known as the Mercerie. It's virtually impossible to get lost because each street name is preceded by the word merceria, such as Merceria dell'Orologio, which begins near the clock tower in Piazza San Marco. Many commercial places, mainly shops, line the Mercerie before it reaches the Rialto, which then explodes into one vast shopping emporium.