After seeing very few to zero new matches over the last week or so, I have about 100 new ones today.

New matches tend to ebb and flow, and I think there are probably a bunch of factors that influence this on AncestryDNA:

-purchasing of AncestryDNA kits is probably highly seasonal (people buy kits for holiday gifts, especially in response to Ancestry's discounts, and may hold off on buying them during the pre-holiday periods when there are no discounts)
-Ancestry's operations might be such that the kits tend to get processed in batches by their lab, rather than getting processed on a purely continuous basis. The lab also might be shut down around the week of Christmas, and then starts to process their backlog of kits in January.

Adam Turner