As Apple unveiled its new music streaming service at WWDC yesterday, competitor Rdio responded by tweeting a welcome note — or rather, a "Welcome, Apple. Seriously." note. Some Twitter users thought it showed "the upmost respect in welcoming competition," but others recognized it as the backhanded compliment it was.

As press statements go it seems pretty friendly, but it's actually a re-run of a famous ad Apple ran in The Wall Street Journal in 1981. The iPhone-maker's original "Welcome, IBM. Seriously." note ostensibly congratulated IBM on unveiling its first ever personal computer, but also took a moment to remind readers that "[Apple] invented the personal computer" as well as dropping some projected industry-wide sales figures into the mix. You can read it as classy, sure, but it's also cocksure.

Rdio might be trying to make the point that when it comes to the music streaming business, it's Apple that is the latecomer and corporate giant — just like IBM was back in the day. And that means Rdio, of course, must be Apple. However, it's worth remembering that after the original "Welcome" ad came out, Apple quickly lost a huge share of the personal computer market to IBM, and only overtook the company in its market capitalization a full 26 years later in 2007. Even if Rdio is Apple in this scenario, it's got a painful road ahead.