  The recent discovery of persistent GRB counterparts at lower frequencies
permits several important conclusions to be drawn. The spectrum of GRB970508 is
not consistent with an external shock origin for both the prompt GRB and the
persistent emission, suggesting that at least the prompt radiation is produced
by internal shocks. Comparisons among three GRB with counterparts (or upper
limits on them) establishes that GRB are not all scaled versions of similar
events. The angular size inferred from the apparent observation of
self-absorption in the radio spectrum of GRB970508 a week later implies that
its expansion had slowed to semi-relativistic speeds. This permits a remarkably
low upper bound to be placed on its residual energy, suggesting either that
radiation has been $> 99.7%$ efficient or that the initial outflow was strongly
collimated. Observations of self-absorbed radio emission from future GRB may
permit direct measurement of their expansion and determination of their
parameters and energetics. We estimate initial Lorentz factors for GRB970228
and GRB970508 $\gamma_0 \sim 100$, and present a solution for the evolution of
a blast wave with instantaneous cooling. The visible flux is predicted to rise
initially as a power of $t$ slightly less than unity, in agreement with
observations of GRB970508.
