iLike, the music service with a massive following on Facebook and increasing popularity elsewhere, has introduced full-song playback on its flagship site, iLike.com. Through its partnership with music subscription service Rhapsody, the site will be offering over 5 million songs from all of the major labels and a variety of indie artists, too. In conjunction with the launch of full song playback, the site is also launching a new self-serve ad platform for concert promoters.

Unfortunately, the full-song playback will be partially restricted for users that aren’t Rhapsody subscribers. Non-subscribers will only be able to listen to a maximum of 25 songs per month, while Rhapsody users under the service’s $12.99 monthly plan will be able to listen to an unlimited number of songs. iLike competitor Last.fm began offering less restrictive playback options in January, but has had issues with keeping its content-providers satisfied (Warner Music Group pulled out of the deal in June).

The new ad-platform, which also launches today, is designed to give concert promoters a way to create feature-rich ads without much effort or technical know-how. Ads will be distributed across iLike’s network (namely their website and social network applications), and will display content depending on a user’s geographical location. On social networks, the ads will also include elements like “invite your friends” and “see who’s going”.

iLike has also announced plans for a new developer platform that will be launching in the near future (likely in the next few weeks). While iLike has offered widgets for syndication in the past, the new platform will allow developers to customize their own web applications.