And why does Tesla want to spend 10 million in an attempt to affect the stock price, which might not even work?
This.
Needless to say this forum is concerned about near term movements in the share price; sadly, this concern can be stronger than concern over the rate at which Tesla grows.
Elon no longer concerns himself with the stock price. His focus is on growth, which has been successfully decoupled from capital raises. He figures that by focusing on growth, the share price sorts itself out eventually, and he'd be right.
Some suggest that more funding can provide faster growth. Elon has refuted this. Again he's right - growth is limited by other factors, such as the rate at which knowledge can be passed to new staff - poor customer service is one symptom of growing too fast - the person on the other end of the communication is simply green, still learning the ropes. Tesla is growing at a phenomenal rate. Patience.
Here's the thing. To move the share price, one has to convince more than half the market that the stock is undervalued, it's like winning an election, you need to sway the slow adopters, people set in their ways. To sell cars, you only need to convince the select group of people who will go to the web site and place an order. They are already keen. The latter does not require mass market advertising - viral advertising, youtube, family and friend networks, twitter, forums like this, reveal nights such as Thursday, they all work too. And like viruses, there's a critical mass where they hit epidemic proportions. At the rate Model 3 is selling, that point is near.
If you read a 'pro advertising' comment, please consider if the motivation is growth, or near term share price. The former will take care of the latter soon enough.