It seems that every time I turn around there's a new aggregator being announced - SharpReader just came out, for instance. A lot of these are using .NET - which is a 20 MB runtime.
BottomFeeder, on the other hand, is a cross platform aggregator. The baseline download (compressed) is a tad over 5 MB, and updates to it are in the 200k to 900k range. I could ship smaller updates - patches - but it seems simpler just to replace the baseline application parcel, and is certainly easier to manage.
Kind of an odd place, having the Smalltalk solution be the smaller, lighter weight implementation - it's not at all what the conventional wisdom on ST is.