Included in those considerations is frequency of transactions and intent. 1 is arguably few enough to not consider it ordinary but if it's 1 per year and the IRS sees you're doing it mainly to avoid taxes it could cause problems.

But you can adjust the stay-alive check frequency to minimize that. 

Blogging is a commitment and a real skill to find the right blend of material and the right frequency for your audience.While I'm now highly skilled at blogging, I'm not sure that I could maintain a successful RE Blog that people would want to read or follow as there is so much excellent subject matter content out there (and here) already and I'd have little value to add.It pretty much comes down to the goal of what you're trying to accomplish.

You want to spell out the amount, the interest rate, when it's computed, the payment frequency, any minimum or maximum payment amount, late fees, etc.The difference between 8 and 9% is 12.5% of the return your lender is getting.

Flipping houses, if conducted with any regularity or frequency (more than a few a year) will subject the IRA to Unrelated Business Income Tax (UBIT), which can be as high as 39.6%.  

Marijuana does not do damage like nicotine from cigarettesIt's all about frequency of use.  

Google youtube and septic tank pumping frequency.

I recommend frequency on prospecting for sites to publish your content and look for relevant places to post.Over time the compounding of content on your site and your link development efforts will drive up your leads which come from your site for free (or your cost to build content/links) as well as your AdWords costs will go down due to Google's QualityScore.

Review Page 3 of IRS Publication 598, which states: “Business activities of an exempt organization ordinarily are considered regularly carried on if they show a frequency and continuity, and are pursued in a manner similar to comparable commercial activities of nonexempt organizations.†An example is given in the publication.

I lifted this out of a BP post.The need for them to secure renter's insurance.In the event of a tropical storm or hurricane watch or hurricane warning, who is responsible to install storm shutters and how far ahead of time etc...Operation and frequency of the sprinkler system - only for SFR properties.