He's providing you with hours of witty social commentary and comedy for free. He's got every right to try and sell some merchandise so that he can get some funding and keep doing just that. Plus, it is not like he constantly mentions them in his videos, he only showcases his stuff at the very end of the video after the content has been delivered.
The ads that are on Youtube before his videos, especially the unskippable ones, is what really rustles my jimmies and should yours as well. Youtube is going to hell in a handbasket, I tells you wut.
Did he force you to look at them? They were accidentally leaked onto the Internet and you had to go searching for them.