I have been looking at apartment rentals on craigslist and have found that a number of them have links to roomster.com. There are already complaints about roomster.com's abuse of credit cards, here on ripoffreport.
The links, some of them disguised through "is.gd", go to roomster.com's home page, not to a specific roomster.com listing.
I thought this peculiar, and Googled key phrases from several of these ads. What I found were STOLEN ADS that had appeared on craigslist in other cities. (i.e., an apartment ad for Denver that links to roomster.com is word-for-word identical to one that appeared a month ago on craigslist in Seattle!)
Obviously, roomster.com appears to be placing phony ads as a way to get people to sign up for their "service."
DON'T DO BUSINESS WITH PEOPLE WHO LIE TO YOU!