Spotify Technology gained more subscribers than expected, but it wasn’t enough for investors who are worried about competition from Apple and Amazon.com.

Spotify boosted its customer base to 180 million in the second quarter, more than the average 178.5 million forecast from analysts. But shares still fell as much as 5.6% in early New York trading.

It marks the second quarter in a row that investors were less than thrilled by results, even as the company delivered on its own forecasts for subscriber growth. One possible concern is that growth of Spotify’s free service appears to be slowing. The company reported fewer users of the advertising-supported tier than a quarter ago, although the base grew by 23% year over year.

“If the slowdown continues we’d miss our guidance expectations and that would be a cause for concern,” chief financial officer Barry McCarthy said in an interview with reporters.

Spotify introduced a new free service in April to make it more attractive to potential customers. The company has used the free service to attract people whom it then tries to convert into paying subscribers.

The music streaming service also took a tax hit that was bigger than it had forecast, contributing to a per-share operating loss of €2.20, it said in a statement on Thursday. Investors have been willing to forgive Spotify’s losses so long as the company keeps adding customers — the kind of approach that worked for Amazon.com and Netflix. Spotify’s sales in the quarter grew 26% from a year earlier to €1.27-billion.

Spotify faces a counterattack from established technology giants. That includes Amazon, YouTube and most notably Apple, whose music service is expected to surpass Spotify in US subscribers in the coming months. — Reported by Lucas Shaw, (c) 2018 Bloomberg LP