As Ars Technica reports, Tumblr will launch ads starting May 2:

As recently as April 12, Kamp told Ad Age that advertising was “a complete last resort.” In 2010, the CEO famously said, in an interview with the Los Angeles Times, that the company was “pretty opposed to advertising. It really turns our stomachs.”

Yesterday, however, 25-year-old CEO added that putting ads on Tumblr Radar would get an advertiser 120 million impressions per day and will be available as of May 2.

I don’t know the reasons for this sudden U‑turn. Some speculate that Facebook acquiring Instagram may have scared Tumblr somehow, but whatever the reason, I hope the Tumblr user experience won’t be too drastically compromised. It’s not clear to me how ads will be shown. Will they appear only when users are browsing other tumblelogs in the Tumblr dashboard? Will they appear in every tumblelog? And where will they be placed? Will they appear in the left or right sidebar? At the end of a post, like in WordPress blogs?

I have a few active tumblelogs, and those I consider most important are The Quillink annotated and Minigrooves, and I’d hate to see them ruined by ads appearing alongside my posts or, worse, above or immediately below the masthead.

My humble request to Tumblr is: Please, please, introduce Pro accounts. Follow other examples (LiveJournal and Flickr come to mind) and give Tumblr users the possibility to pay an annual fee for an ad-free Pro account. It’s also a increasingly common practice in iOS apps, where you’re offered the choice of having a free app that shows ads, and an in-app purchase (or a separate ‘Pro’ or ‘HD’ version) that removes them. I would gladly pay such a fee in exchange of a tumblelog without ads — I’m not even interested in other bonus options or offerings: paying only to remove ads would be absolutely fine by me. I’m sure other Tumblr users — who use their blogs to do more than just post links and funny videos — share my concerns and sentiments.