Is it too strange to begin a review with the cons? Probably, but in this particular case they are more important than the pros. LinkMetro.com is one of the hundreds “link exchange” directories you could find during a five minutes online search.
There’s nothing wrong with link exchanges, and especially not when they are done professionally and the exchanged links are related and relevant for the content of the “host” site. You should see them as a “win-win” traffic exchange. If you hunt for their PR (Google PageRank) value this is no longer as high as it used to be.
Because of spam sites like most of the ones you’ll find at linkmetro.com and because of link farms and other black hat linking practices, the search engines devaluate the links obtained as a result of an “exchange”, especially if the relevancy of the link is low (Why would you list a shoe store on an SEO site, unless you showcase your own SEO portfolio?)
To make a long story short, the most important con against linkmetro: most of the participant sites, with few exceptions, use worthless link farm directories, sometimes not even located on the site they request the link exchange for (why would they get their main site penalized for black hat techniques?), where they’ll add a link to your site, while they expect that you add their links on pages with a decent PR.
Is there a pro for linkmetro? I suppose, if you don’t mind giving your “link juice” to a link farm, thus lowering your PR score considerably and endangering even your Google listings (for linking to bad neighbours) there might be one pro: the user-friendly interface. You can search for related sites easily in the directory, see even the PR of the main index and push on a button to send a link exchange request, which will look like:
“A LinkMetro member has requested a link exchange with 1 or more of your websites (your site <> requester’s site). You may accept or decline this link request by clicking the link below, logging into your account, and clicking the ‘monitor link exchanges’ link.”
Now to the purpose of this entry: do not endanger your SE listings by getting involved in spamdexing practices. If you want to use such a link exchange directory, do check the sites you find before even considering sending them a link exchange request. And remember: exchanging links is just one of the many link exchange strategies used by professional SEOs to optimize your site. You need to employ various techniques to get proper results.