And both have to do with advertising.
Counting all packages indexed in 02packages.details.txt (possibly across multiple tarball versions), two distributions account for 5% of CPAN packages:
Here are the top 10 with the number of index lines each:
GOOGLE-ADWORDS-PERL-CLIENT: 5480 Microsoft-AdCenter: 1628 Shipment: 1197 eBay-API: 1160 BioPerl: 851 Graphics-VTK: 707 DateTime-Locale: 469 Net-Amazon: 455 UMMF: 451 Locales: 426
Together they account for 8.6% of the 135,000 or so currently indexed packages.