Hi, Abby from Tipjoy here. One exciting aspect of tipjoy is that the ranking is determined by the amount of PAID tips something has received. Right now nothing’s yet been paid (except for a little bit we’ve put in ourselves), so the top tip list has the spam you've mentioned. However, as people begin to pay for their tips (by hitting the ‘pay’ button in the upper right corner of tipjoy.com when signed in), the most popular tip list will start to evolve to reflect what’s really worth money to people.
That being said, we're probably going to add a "safe for work" mode, which you can toggle to hide questionable content.