I know they do not allow plugins on wordpress.com and hence no ads. I know I can put adds on own wordpress site hosted on my own domain. But I really like wordpress.com and the ease you can create blogs there. Is there any decent way that I can put my ads on google? Weren’t they allowed the ads before?
Or would anyone encourage me to go with my own site instead of wordpress.com ?
No, you cannot, unless you have 25,000 pageviews/month, as stated here!
http://en.support.wordpress.com/advertising/
Go with hosted or self-hosted solution of WordPress instead.