<i>How rapid is interesting? This depends, but a rate of 10% per week for several weeks is impressive.</i><p>I wish this was a bit more specific -- how long exactly is &quot;several weeks&quot;?  3 weeks (total growth of 33%)?  7 weeks (total growth of 95%)?  13 weeks (total growth of x3.45)?  52 weeks (total growth of x142)?