Xbox live sales

I've heard there are sales for xbox live arcade games and games on demand, similar to steam sales. How do I figure out when these are happening? I don't see like a store hub or anything with announcements.

Aren't they usually on the tail end of spotlight channel?
 
Also I think you have to be a Gold member, I don't remember exactly I haven't used my 360 in awhile.

In terms of specific sales, I don't think there is anything for it. There is though a best selling section in the Live dashboard and Major Nelson's weekly report.

There's a panel under Spotlight that'll say "Deal of the Week" You can check see the weekly special there, or go under recently reduced to see permanent price drops.

I usually just check here. He keeps it updated pretty nicely.

http://www.cheapassgamer.com/forums/showthread.php?t=283304

this is usually when we get more frequent XBLA sales. Can't wait for the end of the year sale.

They have had some really good sales there. I believe it is pretty much always 50% off.