1. Tesla pays off the $452 million Dept of Energy Loan, and this improves their political image and in the long-run will help sales.
Tesla's had difficulty in some states selling direct to consumer, and paying of the DOE loan can help them convince conservative lawmakers to vote on Tesla's side in states like Texas and North Carolina (both have bills on the table).
Also, paying off the DOE loan removes ammunition from a lot of critics who have said that Tesla is just leaching off the U.S. gov't.
2. Tesla puts more than $400 million additional cash into their bank account (they already had over $200m), so now it's well over $600m and close to $700m in cash they hold.
This allow them to speed up a lot of the intiatives they have to roll out infrastructure. First, they can open more stores (especially in Asia and Europe). Second, they can roll out more service centers (all around the world). Third, they can roll out more Superchargers stations (around the world).
Finally, Tesla has an upcoming 5th announcement in a 5-part trilogy and I think Tesla might announce battery swapping stations (for long distance travel). Tesla can now more aggressively roll these out as well.
3. Tesla stock gets a boost of confidence from Elon Musk spending $100m to buy common stock.
Elon Musk is putting his money where his mouth is and is basically saying that at the offering price of $92.24 that TSLA stock is not overpriced but is a fair value to himself buying more stock and to investors.
4. Involving Goldman Sachs and Morgan Stanley in brokering convertible notes and stock increases the credibility and perception of Tesla. Big funds are now starting to invest in Tesla after their blowout 1st quarter earnings report (WSJ reported in another article that European funds and large-cap funds are starting to invest). Recently Morgan Stanley sent a client note saying that after the 1st quarter earning report saying that viability was no a problem for Tesla. This opens up TSLA stock to a whole new crowd of investors because Tesla's risk has been dramatically reduced.
Overall, I think this is a great move by Tesla.