The likelihood that the targeted companies hire you afterwards is VERY low. You basically just shat all over their baby.<p>On the other hand, other companies (who weren't shat on) will stand up and take notice.<p>Spec work is only when it's by request, and the request came from people who benefit from it (e.g. "show me how you'd do this before I pay you").<p>This isn't spec work, it's publicity-seeking. :)