I would actually take a more optimistic view of abstracts than others here. Any of the three Ps (Publication, Poster, or Presentation) are always good for an application
1) less than 25% of applicants have ANY PPP. This would include Campus wide student symposium or journal, regional meetings, small publications, etc
2) less than 5% of applicants has any PPP in a major setting such as national society or peer reviewed paper