The terms are very similar. The context of their use is important. Say someone asked you whether you like tennis. If you had played in the past, you could say "I love it" If you were playing at the time, you could say "I'm loving it" The latter term is more for an action that is current at the time, but as I said both could be interchanged.

The verb "love" has a stative meaning and is not used in progressive tenses. The expression "I'm loving it" is an advertising gimmick from McDonald's. In other words, love is not something we do, it's something we have. Big corporations employ advertisers that are well known for using idioms, puns and improper or irregular language in their efforts to sell. Here is a website to tell more: http://www.learnenglish.de/grammar/verbstative.html Yours was a good question!

McDonalds uses "I'm loving it" BECAUSE it is bad grammar. When we hear something that is incorrect, we notice it; therefore, people pay more attention (which is what any advertising agency really desires). However, if you start to say, "I'm loving it," you will sound like an idiot.

In my mind "I'm loving it" is grammatically incorrect, although we do often use it in our daily spoken language. So technically speaking we should never use "I'm loving it." Even if it's at the time of speaking, it should be "I love it." For example "How's your mango juice?" "Oh I love it!" NOT "I'm loving it."

"I'm loving it" is violation of grammar because "love" is a verb of state i believe McDonald's should be fined for this... and such ad should be prohibited worldwide