Brand advertising on Twitter

I'd like to talk about Twitter and advertising/brand promotion.
This may sound very random, but it's something I've been thinking about recently. I obviously don't have anything to sell or promote - I'm just me. Other people however do. Companies and brands have twitter accounts and a lot has been made in the press recently about bad PR from certain brands.

Now before I really get into it, a quick Twitter lesson for you. Sorry if I'm teaching you to suck eggs here, but it's important (IMO), and some people don't seem to get this. To me it's one of the most important aspects of Twitter.
When you tweet something, anyone can see your tweet by looking at your Twitter Feed. As can anyone who follows you - they get it straight on their main feed.
If you start the tweet off addressing it to another user, it will only appear on your followers feed if they also follow the other person.
Lets say you follow me, and I tweet Burts Crisps (@BurtsChips) or Pataks Curry Club (@PataksCurryClub). You will only see that if you also follow them.

So I could say "@BurtsChips Your crisps are amazing, I love them" which is great PR for them, except only someone who already knows about them (because they're following too) will see it. And they will know I'm right.
However, if I tweet "Hey @BurtsChips, you're crisps are amazing", then all my followers will see it.

Why would I do this? Because it helps Burts. I've just opened them up to an audience of 200+ people.
Maybe one of my followers is in a shop one day, spots a packet on the shelf and thinks "Ah ha! That's what John was on about! I'll try me some of them!"

Naturally I don't get any financial reward for this. However to reward us, brands often ReTweet our tweet. 
So now I get advertised to 5000 people. maybe a few of those may look at my feed and like what they see and maybe follow me.
Of course, I don't gain anything for gaining new followers, apart from a mini ego boost.

But that, in a nutshell is how to help brands you like. My advice is don't go overboard on spamming your followers with everything you like, but a couple a day can help :)