Google Inc.'s (NASDAQ: GOOG) share price has been on a roller coaster ride this year. Just over a month ago, the company's shares stood at their highest-ever level, reaching right under $750. In a month, shares settled down into the low $600s and closed yesterday right over $643. What a ride it has been -- from the $400s to the mid-$700s all in one year.

So, it comes as no surprise that yesterday a Credit Suisse analyst has raised his price target on Google shares to $900, representing the highest official price target on Wall Street. The reasons behind the target include the usual suspects: Google will realize gains as advertisers move increasingly online. Yes, that makes sense.

The unknown is the amount Google will grow based on that coming influx of more ad dollars. Of course, the company has had no problems growing substantially every single quarter its been a public company. so why should it slow now?

The analyst, Heath P. Terry, said Google is the best internet investment as all advertising goes digital. Although Google's ad revenue "all eggs in one basket" approach has been hailed as a one-trick pony, apparently Terry thinks the company can keep running the trick over and over again. Do you agree?