There's little wrong with investing in SBA Communications (SBAC 0.12%). It has a proven business model and a great track record in a growth industry that still has a lot of room to run.

Along with rivals American Tower (AMT 0.63%) and Crown Castle (CCI 0.79%), it's one of the pioneers in the cell tower business, and it, too, is investing in its own mix of traditional cell towers, data centers, distributed antenna systems for buildings and rooftops, fiber, and the other apparatus of the 5G rollout. All three of these tower operators went public in the late 90s, and SBAC's normalized total return, in fact, has handily outpaced American Tower and Crown Castle so far this century, as the chart below shows.

SBAC Total Return Price Chart

SBAC Total Return Price data by YCharts

Yet, I own Crown Castle and American Tower stock with plans to hang on to both. But I don't own any SBAC stock. Why? It's about dividends and diversification.

Let's get REIT about income.

Like its two rivals, SBAC is a real estate investment trust (REIT), a pool of income-producing properties obligated by tax law to pay out at least 90% of its taxable income as dividends. I'm a retiree with a focus on income, with a side of growth in my thinking about my investments. That's where the other two have an edge.

SBAC stock is currently yielding about 1.6%. American Tower, 3.5%. Crown Castle, 6.4%. That's quite a difference and not a particularly recent aberration.

 AMT Dividend Yield Chart

AMT Dividend Yield data by YCharts.

You'll notice right away that this chart only begins in 2019. That's because SBAC only became a REIT in 2016 and started paying dividends in mid-2019. Crown Castle and American Tower both have much longer records of a commitment to dividend growth.

And even though Crown Castle's total return still badly lags the other two, I'm an income investor and don't plan to sell my shares anytime soon. 

In fact, if I was buying shares in an infrastructure REIT right now, I'd probably lean toward Crown Castle. Analysts give all three significant upsides of 35% to about 40%, and all aspects of wireless growth seem promising right now, but SBAC is more expensive by one key measure: the ratio of share price to funds from operations (FFO) per share.

Currently, on a trailing-12-month basis, it's 19.6 for American Tower, 18.3 for SBAC, and 12.2 for Crown Castle. All things being equal, which they never exactly are but are pretty close in this case, that would give the edge to Crown Castle.

Too much of a good thing?

So, besides the relatively paltry payouts, a major reason why I don't own SBAC is that I already own AMT and CCI shares in my income-heavy portfolio. These two companies have large, diversified portfolios that are well-positioned to generate income and growth over the long term, and they provide the exposure I feel I need to the burgeoning wireless sector.

Owning all three companies would feel redundant and maybe add a little risk of overexposure to a sector where share prices do tend to follow the tech market, especially the big wireless carriers these tower companies depend on for so much of their revenue. That really only matters when you decide to sell, of course, but that will happen someday.

SBAC wouldn't meaningfully improve my portfolio's diversification and certainly not its income. For these reasons, I've chosen not to invest in SBAC at this time despite its strengths. It's a great company, but it's already pricey given its yield, and there's no reason to cash out on the other two. At least not now.