Eric Ries has written extensively on how he initially spent months engineering cross-IM compatibility for IMVU, and then when they shipped it he found that a large number of their customers saw separate IM networks as a strength, not a weakness.<p><i>They&#x27;d say, &quot;Hey, that guy was neat; I want to add him to my buddy list. Where&#x27;s my buddy list?&quot; And we&#x27;d say, &quot;Oh, no, you don&#x27;t want a new buddy list; you want to use your regular AOL buddy list.&quot; You could see their eyes go wide, and they&#x27;d say, &quot;Are you kidding me? A stranger on my buddy list?&quot; To which we&#x27;d respond, &quot;Yes; otherwise you&#x27;d have to download a whole new IM program with a new buddy list.&quot; And they&#x27;d say, &quot;Do you have any idea how many IM programs I already run?&quot;<p>&quot;No,&quot; we&#x27;d say. &quot;One or two, maybe?&quot; That&#x27;s how many each of us used. To which the teenager would say, &quot;Duh! I run eight.&quot; It started to dawn on us that our concept was flawed.<p>Our early adopters didn&#x27;t think that having to learn a new IM program was a barrier.</i><p><a href="http:&#x2F;&#x2F;www.inc.com&#x2F;magazine&#x2F;201110&#x2F;eric-ries-usability-testing-product-development.html" rel="nofollow">http:&#x2F;&#x2F;www.inc.com&#x2F;magazine&#x2F;201110&#x2F;eric-ries-usability-testi...</a>