There are three ways to exhibit your 3D model on Bld3r: upload the STl file, link to a 3D model elsewhere or link to a Torrent for larger downloads.
The site also offers some tutorials and community features, but the key will be adding more 3D models.
As you can imagine, a new repository such as Bld3r does not have nearly as many models as the big sites like Thingiverse, but it does offer an alternative. They say:
Bld3r is a community for 3D printing tinkerers and enthusiasts.You might love sharing your creations with others or you might simply want to print cool, quality designs. In any case, everyone here wants the best objects.Print freely and responsibly.