  Early X-ray afterglows recently detected by {\it Swift} frequently show a
phase of very shallow flux decay lasting from $\sim 10^{2.5} $s up to $\sim
10^4 $s, followed by a steeper, more familiar decay. We suggest that the flat
early part of the light curve may be a combination of the decaying tail of the
prompt emission and the delayed onset of the afterglow emission observed from
viewing angles slightly outside the edge of the region within the jet with
prominent afterglow emission, as predicted previously. This would imply that a
significant fraction of viewers get very little external shock energy along
their line of sight, and, therefore, see a very high $\gamma$-ray to kinetic
energy ratio at early times. The early flat phase in the afterglow light curve
implies, in a rather robust and model independent manner, a very large
$\gamma$-ray efficiency, typically $\gtrsim 90%$, which is very difficult to
extract from baryons by internal shocks.
