I have been contacted by tons of these crowdfunding promoters on my Kickstarter page and email too since my first crowdfunding project a few years ago.
I signed up with Ayudos a second time because of a really good first experience and they did a great job the 2nd time around as well.
After a half hour free crowdfunding page review and some feedback on changes to make, they started the social media blasts right away and even had me featured on a few blogs and related websites within a few days.
I did see a significant boost in views and traffic to my project pages and did result in higher ranking on Kickstarter which means more eyes on my page and backers.