This paper examines the effects of competitive dispersion on both personalized pricing and uniform pricing in an environment where the number of competing firms varies across consumers. We define an increase in competitive dispersion as a mean-preserving spread in the distribution of the number of competing firms. We provide conditions under which greater competitive dispersion decreases the average markup under uniform pricing, but increases the average markup under personalized pricing. We find that the degree of competitive dispersion has a significant effect on markups even in the competitive limit where the expected number of competing firms becomes large. Relative to uniform pricing, personalized pricing may either benefit or harm consumers depending on the degree of competitive dispersion. If competitive dispersion is relatively low, personalized pricing benefits consumers and harms firms relative to uniform pricing. However, if competitive dispersion is sufficiently high, personalized pricing harms consumers and benefits firms.