Personally I wouldn't notice it if it did increase spam, since I'm immune.
But seriously, I researched it before trying it and it is reputable with no adware, spyware or anything like that, and it works as advertised - the crawlers came. Used it on two sites and a friend who posts here used it on his as well. neither of us noticed any resulting spam or any type of attacks on our sites.
Wouldn't just about anything one does to get a site out there have some chance of increasing spam?