I've been using promotional offers from E*Trade for years now and have been very impressed with them. Over the last couple of years I've collected well over $10,000 in 'free' money and am collecting more this year.
Here is the typical deal:
Deposit Amount Cash Credit
$25,000-$99,999 $200
$100,000-$249,990 $500
$250,000-$499,999 $1,000
$500,00-$999,999 $1,500
$1,000,000+ $2,500
As you can see; if you have $1M to move you are much better off moving it in 4 increments of $250K. $4K bonus vs $2.5K bonus.
For me, it all started out when I needed to rollover a 401K from MegaCorp due to a job change. E*Trade gave me a free iPad as a reward at the time and back then a free iPad was a really cool thing for me (they were just introduced). Since then I started moving bits and chunks of my regular portfolio as the rewards motivated me to do so. Note, occasionally they are much better than the table listed above.
Anyway, as your portfolio grows E*Trade will assign a human to you as sort of a customer service thing. These guys often want to help you 'manage' your assets, but you can decline these offers (which I have always done). I use this person to help with logistics or just basic grunt work and have been really impressed with his service. Examples are being charged annoying 'wire fee's to move a large chunk of cash or needing something like a new ATM card when I'm on the road; he will just solve the problem and it's a nice benefit.
Like many of you I also hate the headaches related to a x-fer. But these days there are few. I have stocks I bought a very long time ago and held them at a company called 'Regal Discount Securities'. That broker is long gone now and I've had to track my cost basis from that no matter where I put the stocks. The stocks were x-ferred to Options Xpress (with no free money bonus and all of the headache). Options Xpress was bought by Charles Schwab and so I was faced with another mandatory x-fer. This is when I made the shift to consolidate at E*Trade over time and with incentives. Sometimes you can not avoid the hassles of an x-fer, but in my experience E*Trade has been the best to work with. By the way, E*Trade lets you x-fer over the stocks (you don't have to sell them in case you were curious) and the mandatory IRS cost basis tracking that goes with more recent purchases follows those stocks around. So no additional work there.
Another thing to mention; you get the bonus for every account you work with. So I have a regular margin account, an IRA account, and a Roth account. My wife also has an IRA account and a Roth account which I manage. So each of these accounts collects these cash incentives. Also, each gets free trading and other benefits associated with these promotions. Schwab wanted me and my wife to sign and notarize a bunch of complicated paper docs to allow me to continue to manage my wife's accounts, where E*Trade did almost all of this online.
Sorry for the long post, but I have a lot of experience with this topic.